X-factors for the 2026 MLB Season: NL West

As we get ready to usher in the new MLB season, the Just Baseball show has been going division by division, breaking down each team’s outlook for 2026. A large part of this outlook depends on various X-factors. These can be key role players, needed starting pitching performers, or even stability at the managerial position.

This year, the NL West features the defending World Series champs, teams looking to make deeper playoff runs, teams looking to find their way back to October, and the Rockies.

As for every team, there are some players on each NL West club who will play a larger role than others in controlling their team’s destiny. We will be breaking down these players and explaining how they can constitute success for their respective clubs in 2026.

Los Angeles Dodgers

X-factors: Tanner Scott & Roki Sasaki

These two players entered the 2025 season as new additions to the LA clubhouse, but didn’t live up to expectations. Their expected roles are very different in 2026, but LA needs to see a step up from both of these players to continue its dominance this year.

With the team signing Edwin Díaz to a three-year, $69M contract in December, Tanner Scott no longer holds the closer position heading into this season.

Scott was signed to a four-year deal of his own ahead of 2025, but failed to live up to those expectations in his first year as a Dodger. Scott posted a 4.74 ERA and 4.70 FIP in his 57 innings in 2025.

The lefty’s 2025 was defined by dramatic changes in batted ball control. After spending his Marlins years inducing soft ground balls to hard-hit fly balls. Among 229 qualifying pitchers between 2024 and 2025, Scott had one of the five steepest increases in hard-hit rate (+14.8) and exit velocity (+6.5 mph), while suffering the fourth steepest drop in groundball rate (-12.3%).

Now serving as the Dodgers’ setup man to Díaz, Scott will need to reverse course to get back to his old form. Although last year was undeniably bad, there were some silver linings.

Scott’s 7.2% walk rate was a career low and a 5% decrease from last year. While his strikeout rate has dipped over the last two seasons, his Whiff% and Chase% are still elite. An effective version of Scott is still in there, but it all lies in the batted balls he allows.

As for Roki Sasaki, 2025 was not the rookie season he and his team had planned for. The 23-year-old made eight starts before being sidelined due to a right shoulder injury. Those eight starts were less than impressive; he posted 24 strikeouts and 22 walks in 34.1 innings. His 4.72 ERA and 6.19 FIP left fans wanting more, and more was on the way.

Sasaki returned from his injury just in time to be an effective bullpen arm down the stretch. In nine postseason appearances out of the pen, Sasaki got the job done with a 0.84 ERA. Though his 3.70 FIP indicated more of the same struggles, it was enough to close out some key games for LA en route to another World Series championship.

As of right now, Sasaki is projected to start the season in the back end of the Dodgers rotation, but could lose that spot upon Blake Snell’s return to the injured list.

For him to avoid that outcome, Sasaki will need dramatic improvements to his strikeout and walk rates. His 3.7% K-BB% in 2025 ranked 11th worst among the 475 pitchers to throw at least 30 innings. This means being more deceptive by upping his 22.1% whiff % and 22.3% chase %, both of which were severely below league average.

With injuries plaguing the Dodgers’ rotation for several years now, a healthy and revamped Sasaki can go a long way in helping this team reach its full potential in the regular season.

San Diego Padres

X-factor: Joe Musgrove

The departure of Dylan Cease on an eight-year free agent contract to the Toronto Blue Jays leaves the Padres rotation in a dire spot. The team was able to retain Michael King on a three-year deal, but the depth after he and Nick Pivetta is rather bleak.

San Diego is expected to roll out guys like Randy Vasquez, Germán Márquez and Walker Buehler as part of its Opening Day rotation; three guys who combined for a 5.13 ERA, 5.32 FIP and 5.3% K-BB% in 386 innings pitched last year.

Other options include JP Sears, Matt Waldron, Marco Gonzales and Triston McKenzie. A team kicking and screaming to keep its championship window open has to have better pitching options, so Joe Musgrove perhaps represents its biggest hope.

Entering his age-33 season, the San Diego native last pitched in the 2024 NL Wild Card series against the Braves before receiving Tommy John surgery, taking him off the field through 2025. It appears Musgrove will likely remain on the IL at the start of the 2026 season as he continues his recovery, but he may return soon after.

Even before the elbow surgery, 2024 was a step back for Musgrove. His 3.88 ERA and 3.96 FIP were both his worst in any season since joining the Padres in 2021. While his strikeout and walk numbers remained elite, contact against him was too hard and too high.

For the first time in his career, Musgrove’s 2024 featured an opposing barrel % above 10% and average exit velocity above 90 mph. Along with that came a career high 29.7% fly ball rate and career low 41.7% groundball rate. This factored into his 1.26 HR/9 in 2024, his highest since 2017.

At the forefront of this regression was Musgrove’s four-seam fastball, his most commonly thrown pitch from 2023-2024. Opponents went from slugging .276 against it in 2023 to .530 in 2024. Simply put, hitters were getting a better piece of it. Its average exit velocity went from 85.7 mph in 2023 to 92.9 in 2024.

For him to succeed in 2026, he’ll need to either improve or ditch this pitch. Luckily, when it comes to the latter, he has options.

Musgrove threw seven different pitches in 2024, four of which he threw at least 20% of the time. A curveball that posted a 2-degree launch angle, a cutter that produced a 1.5 RV/100, and a sweeper that averaged 45 inches of drop and 17 inches of sweep.

San Francisco Giants

X-factors: Jung Hoo Lee & Tony Vitello

The Giants are trying to escape the purgatory of .500. After winning an unexpected 107 games in 2021, San Francisco has won between 79-81 games in each season since. But one player and one coach could play a significant role in helping this team ascend.

What does a career year for Jung Hoo Lee look like? Perhaps we got the answer early last year. From the start of the season through late April, Lee posted a .319 AVG and .901 OPS. His 1.2 fWAR over this stretch was tied for 14th highest among all position players. He went on to post a .691 from May 1st on.

There’s one number that can sum up the success Lee saw in April compared to the rest of the season. Over his dominant stretch, he posted a 31% line drive rate, the 21st highest among 200 hitters with at least 50 batted balls in that span. After that, his line drive rate never exceeded 26.2% in any other month, and it dipped below 20% in June and July.

Lee’s profile as a hitter is fairly defined. He is a great contact hitter that doesn’t hit for much power, especially as a lefty at Oracle Park. Line drivers are his best friend; if he’s not hitting them, he’s not thriving.

As for Vitello, this is an experiment that not only could change the trajectory of the franchise but also usher in a new era of managerial hires around the league. The former Tennessee head coach is looking to prove that it’s possible to make the transition from college to the pros.

Vitello is the Giants’ third manager in the last four seasons, bringing a very different experience to the dugout. In eight years with the Volunteers, he led Tennessee to a 341-131 record, three College World Series appearances and the 2024 National Championship. While there, he coached players like Garrett Crochet, Christian Moore, and the Giants’ Drew Gilbert.

Arizona Diamondbacks

X-factors: Jordan Lawlar & Brandon Pfaadt

After shocking the world and appearing in the 2023 World Series, Arizona has yet to return to the playoffs. The team will look in part to these two former marquee organizational prospects to make it happen.

2021 first-round draft pick Jordan Lawlar has struggled in 108 career MLB plate appearances. The 23-year-old is slashing .165/.241/.237/.478 in this small sample. But he did show us something towards the end of last season. From September 2nd on, he hit .333 with a .918 OPS. All this while decreasing his strikeout rate from 48.4% in his first 11 games of 2025 to 24.4% in his final 17 games.

Was this hot stretch sustainable? Not in the way it happened.

His 42.9% line drive rate in September 2025 was the highest among the 334 hitters with at least 25 batted balls throughout the month. His 57.1% pull rate also ranks tied for seventh highest. While these are great traits for any hitter to have, they alone likely cannot be replicated over a full season to that extent.

In a limited sample of 74 PA last year, Lawlar struggled to make hard contact. His 87 mph average exit velo, 34.1% hard-hit rate and 4.9% barrel rate were all below league average. Combine that with a 35.1% strikeout rate, and it’s hard to see what Lawlar did well in the entirety of his last season. He’ll need to make better and more consistent contact to be an impact bat for the D-backs.

With Merrill Kelly starting the year on the IL and Corbin Burnes still on the shelf, Brandon Pfaadt is among those in the rotation who will need to step up. Pfaadt experienced a regression year in 2025, putting up a 5.25 ERA and 4.22 FIP, both at least half a run higher than 2024.

Over the years, Pfaadt has switched up his pitch usages. In 2023, he threw a four-seam fastball 45% of the time. In 2025, he led with his sinker, and didn’t throw any pitch more than 23% of the time.

Unfortunately, he’s yet to find a pitch that clearly stands tall above the rest. In 2025, only two of his six pitches posted a positive RV/100. One was his sinker, which only reached 0.6. The other was his cutter. It reached a solid 1.5, but he only threw it 9.2% of the time, less frequently than anything else in his arsenal.

Pfaadt needs a clear go-to pitch to find success this year. If he wants it to be his sinker, he’ll need to drop its opposing average exit velocity from 94.1 mph. If it’s his four-seamer, he’ll need to drop the 55.5% hard-hit rate against it. If it’s his sweeper, he’ll need to decrease the 21.2% HR/FB rate against it, the highest against any sinker with at least 25 fly balls against it last year.

Colorado Rockies

X-factor: Chase Dollander

Barring a miracle, the Rockies are not making the playoffs. Hell, even a winning season would be considered a massive win.

The way to evaluate success for the 2026 Rockies has more to do with development than winning. If someone like Chase Dollander can prove himself as a vital part of the next Rockies core, it would be a big step towards building the next winning team.

It wasn’t a pretty rookie season for Dollander, who owned a 6.52 ERA and 5.53 FIP in 21 starts and 98 innings pitched. His strikeout rate dipped from 33.9% in A+ and AA throughout 2024 to just 18.6% in the majors last season. His walk rate also rose from 9.4% to 11.1% in the same span.

Like most Rockies pitchers, Dollander had a hard time adjusting to the high altitudes of Colorado. But this was perhaps the worst case of Coors Field woes we’ve ever seen.

In 10 starts away from Colorado, Dollander posted a respectable 3.46 ERA and 4.33 FIP. But in his 11 starts at Coors, it was an abysmal 9.98 ERA and 6.90 FIP. Of the 250 Rockies pitching seasons with at least 35 innings pitched at home, Dollander was the worst at run prevention.

Dollander will have to figure out how to handle his home ballpark and increase his swing and miss numbers in 2026. Although his results didn’t reflect it last year, he does still show signs of why he was a top 10 draft pick in 2023.

Dollander’s four-seam fastball averaged 98 mph, the third highest among pitchers to throw at least 750 of them, trailing fellow top draft picks Paul Skenes and Hunter Greene. His curveball, the lone bright spot in his arsenal last year, allowed an opposing .161 average, .207 slugging and 35.7% whiff rate.

The Rockies haven’t had a starting pitcher post an ERA+ above 110 in a qualifying season since 2018 (excluding 2020). Fortunately for the 24-year-old, the bar to impressing his fanbase is not high, especially after last year. If he can look like a frontline starter this year, it would go a long way for morale in the Mile High City.

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