MLB clubs have started paring down their rosters in preparation for Opening Day, but just because a player doesn’t make the cut doesn’t mean he won’t make a sizable impact on the season. Top prospects will get their chance to shine. There will be big Trade Deadline acquisitions. And players who begin the year on the injured list will make their long-awaited returns.

With White Sox outfielder Eloy Jiménez is likely to be out until late September, if not the entire season, due to a torn left pectoral muscle, the most important injury rehabbers heading into the 2021 campaign all happen to be pitchers.

That’s fitting in 2021, as this year will likely be marked by how teams cover the innings increase after the pandemic-shortened ‘20 season. It’s going to take an all-hands-on-deck approach, and contenders that can inject their pitching staffs with fresh, effective arms in the middle of the season are going to have a leg up.

Some of these hurlers might be on the mend until summer, but each has the potential to dramatically affect the postseason picture.

Carlos Carrasco, RHP, Mets
Acquired from Cleveland along with Francisco Lindor in February’s blockbuster trade, Carrasco tore his right hamstring running sprints on the field last week. One source told MLB.com’s Anthony DiComo that he expected Carrasco to miss six to eight weeks. Carrasco made a successful return from chronic myeloid leukemia late in 2019 and was back to his old self last season, recording a 2.91 ERA with a 10.9 K/9 rate in 68 innings. In a division that figures to be one of the most competitive in baseball, how quickly the 34-year-old makes it back could very well decide where the Mets finish.

Zac Gallen, RHP, D-backs
Gallen has quietly become one of the most reliable pitchers in the National League, registering a 2.78 ERA in 27 career starts, but he won’t be available when 2021 begins after sustaining a hairline stress fracture of his right lateral forearm at the radial head. This type of injury doesn't have much of a precedent in baseball, so it’s difficult to predict when Gallen might be back. The D-backs were going to have a tough time contending with the Dodgers and Padres even with a healthy Gallen. That said, his return could help them play spoiler this summer. Arizona has 15 games against the Dodgers and 13 against the Padres after the start of June.

Dinelson Lamet, RHP, Padres
Lamet exited his final start of the regular season last September with an elbow injury and missed the playoffs, putting a damper on his impressive breakout. The Padres brought him along slowly this spring, making the right-hander unlikely to be part of the Opening Day roster. San Diego added Yu Darvish, Blake Snell and Joe Musgrove in the offseason and has top prospect MacKenzie Gore waiting in the wings, so the Friars can afford to give Lamet some extra time as a way to limit his workload. But if the Padres are really going to wrestle the NL West title away from the Dodgers, they’re likely going to need Lamet, who had a 2.09 ERA with a 0.86 WHIP and a 12.1 K/9 rate last season.

Nate Pearson, RHP, Blue Jays
Would Pearson (MLB’s No. 10 prospect) have cracked Toronto’s rotation if he didn’t suffer a right groin strain in his first spring outing? It’s tough to say. The righty debuted with five scoreless innings last July, but he struggled in his next three starts before being shut down with right elbow tightness. The injury caused him to miss more than a month, preventing him from building up his innings, though he did return to make a dominant relief appearance against the Rays in the AL Wild Card Series. The Blue Jays could hold him back early in 2021 to control his workload before unleashing him during the summer. With 100-mph gas and three other average to above-average pitches, the 24-year-old has frontline-starter potential. Toronto has some uncertainty in the rotation behind Hyun Jin Ryu, but a rebound from Robbie Ray and a breakout from Pearson could change that.

Chris Sale, LHP, Red Sox
Sale was one of MLB’s top pitchers from 2012-18, making the All-Star team and finishing sixth or better in AL Cy Young Award voting in all seven of those seasons while posting a collective 2.91 ERA with a 10.9 K/9 rate. Although the southpaw dealt with left elbow problems in 2019 and recorded a career-high 4.40 ERA, he still compiled 218 K’s in 147 1/3 innings. Expected back from Tommy John surgery sometime in June, Sale could reclaim his spot as Boston’s ace and help the Sox put last year’s flop behind them.

Luis Severino, RHP, Yankees
It wasn't long ago that Severino was the Yankees' No. 1 starter, with consecutive All-Star seasons, a 3.18 ERA and a 10.5 K/9 rate over 2017-18. But the righty missed most of 2019 with rotator cuff inflammation and a lat strain, and all of '20 after undergoing Tommy John surgery. With Corey Kluber, Jameson Taillon and Domingo Germán having thrown one inning combined in the Majors last season, Severino could prove to be an important in-season addition to New York’s rotation.

Mike Soroka, RHP, Braves
Coming off a 2.68 ERA and a second-place finish to Pete Alonso in NL Rookie of the Year Award voting as a 21-year-old in 2019, Soroka tore his right Achilles in his third start last season. Max Fried and Ian Anderson stepped up to carry Atlanta’s rotation in Soroka’s absence, and the club signed veterans Charlie Morton and Drew Smyly in the offseason. If Soroka can make a healthy return and pitch like he did two years ago, the Braves could have one of the best rotations in the game.

Noah Syndergaard, RHP, Mets
The second Mets pitcher on this list, Syndergaard is in the final stages of his recovery from Tommy John surgery. At some point later this season, the Mets could field a rotation of Jacob deGrom, Marcus Stroman, Carrasco, Syndergaard and either Taijuan Walker or David Peterson. Thor allowed more earned runs than any NL pitcher in 2019 and made 32 starts combined in the two years before that, but his stuff has always been top notch, and he’ll be pitching for his next contract when he returns to the hill.

Framber Valdez, LHP, Astros
At one point, it looked like Valdez needed season-ending surgery on his fractured left ring finger, but a follow-up exam showed significant healing. The left-hander is still out indefinitely, but his eventual return could be a massive boost for a Houston club that is likely to be without Justin Verlander (Tommy John surgery) for most or all of this season. Valdez recorded a 3.57 ERA over 70 2/3 innings in the regular season a year ago before dominating in the playoffs, and his ability to miss bats and keep the ball on the ground gives him a strong chance to build on that success.