As the Hot Stove has simmered over the past few months, clubs around the Majors have sought to improve their lineups by spending money on free agents and pulling off trades.
But for some, a potentially significant "addition" already resides on the roster.
Below is a look at six position players, each of whom suffered an injury (or two) that limited him to fewer than 30 games in 2016. Each should be ready for the start of the 2017 season and has shown the ability, when healthy, to make a sizable impact.
Greg Bird, 1B, Yankees
The left-handed batter raked throughout his time in the Minors, and his Major League debut in 2015 could not have gone much better. Bird played 46 games after joining the Yankees in mid-August and batted .261/.343/.529 with nine doubles, 11 home runs and 31 RBIs. His 137 weighted runs created-plus (wRC+) was tied with the likes of David Ortiz and J.D. Martinez for 23rd among those with at least 170 plate appearances.
But Bird's follow-up effort ended before it began, as he underwent surgery on the labrum in his right shoulder and missed the entire 2016 season. He did make it back for the Arizona Fall League, where everything checked out well in terms of his health. Now 24 and no longer playing in the shadow of retired slugger Mark Teixeira, Bird could retake his spot as the Yankees' first baseman of the future. That said, he'll have to fight for it. New York plans to hold a Spring Training competition between Bird and Christopher Austin, a right-handed hitter who went deep five times in 83 at-bats as a rookie last year.

Michael Brantley, LF, Indians
As recently as 2014, Brantley finished third in the American League MVP race and fifth in the AL with 6.0 wins above replacement (WAR), according to FanGraphs. An All-Star that year, he hit .327/.385/.506 (151 wRC+) with 20 homers and 23 steals. Brantley followed that up with another solid season (3.7 WAR) but then underwent right shoulder surgery that November. A year later, he once again is stuck in rehab mode, following a season that was magical for the team but frustrating for Brantley.
The 29-year-old played only 11 games in 2016 and underwent another surgery in August. This time it was on his right biceps, and the hope is that he will be ready for Spring Training and part of the Opening Day lineup. Much remains uncertain regarding Brantley's status, but having signed Edwin Encarnacion to share first base and DH duties with Carlos Santana, Cleveland needs Brantley to play the outfield. Even something close to Brantley's 2015 production would give a major boost to the Tribe's hopes for a return trip to the World Series.

Mike Moustakas, 3B, Royals
The 2015 season brought not just a title to Kansas City but also a breakout for Moustakas. The No. 2 overall pick in the '07 Draft posted 3.6 WAR and finished fifth among third basemen with a 122 wRC+, batting .284/.348/.470 with 22 homers and 82 RBIs. Moustakas then picked up where he left off, smacking seven homers in his first 19 games last season and slashing .258/.314/.536 before suffering a thumb injury in early May. His return lasted two games before he tore the ACL in his right knee and underwent season-ending surgery.
The 28-year-old now has just one season remaining before he is scheduled to reach free agency, along with teammates such as Lorenzo Cain and Eric Hosmer. If the Royals are going to make another run with that group, a healthy Moustakas would go a long ways, as the rest of the team's third basemen (mainly Cheslor Cuthbert) combined for only 0.3 WAR last year.

A.J. Pollock, CF, D-backs
Pollock put together a solid 2013 and was excellent in an injury-shortened '14, but he truly blossomed into an all-around star in '15. He won a National League Gold Glove Award in center and was the only player in MLB to have a 20-30 season, hitting .315/.367/.498 (131 wRC+) with 20 homers and 39 steals in 46 tries (84.8 percent). That made Pollock the game's fourth-most valuable outfielder (6.5 WAR), behind only Bryce Harper, Michael Trout and Yoenis Cespedes.
Then Pollock fractured his right elbow shortly before Opening Day, erasing almost his entire 2016 campaign. While Pollock finally made it back in late August, he played only 12 games -- homering twice and stealing four bases -- before suffering a season-ending groin strain. The 29-year-old's return should be a boon to the 93-loss D-backs, whose center fielders ranked 27th in MLB in WAR.

Pablo Sandoval, 3B, Red Sox
Sandoval's Boston tenure certainly has not gone as planned since he signed a five-year, $95 million deal before the 2015 season. The 30-year-old switch-hitter struggled mightily in his first year with the club, lost his starting job last spring, then took seven regular-season plate appearances before undergoing surgery on his left shoulder.
Yet all indications are that Sandoval is now healthy, has been working diligently and is in considerably better shape than the last time he suited up for the Sox. The club seemingly gave him a vote of confidence by trading both Travis Shaw and top prospect Yoan Moncada this offseason, clearing the way for Sandoval to regain his job at the hot corner. Considering that in his last three years in San Francisco, Sandoval posted a 114 wRC+ and averaged 2.5 WAR, that development could work out quite well for both sides.

Kyle Schwarber, LF, Cubs
The fourth overall pick in the 2014 Draft, Schwarber established himself as a force at the big league level just a year later, hitting .246/.355/.487 with 16 home runs in only 69 games as a rookie. An outfield collision in the Cubs' third game of 2016 caused torn ligaments in his left knee, but Schwarber made a miraculous and effective return as the Cubs' World Series DH.
Now it's time to see what Schwarber, who turns 24 in March, can do over a full season. His defense in left field remains a significant question mark, and the Cubs have a loaded depth chart, but manager Joe Maddon will find a way to keep Schwarber's bat in the lineup -- maybe even as William Fowler's replacement at leadoff. Steamer projects the left-handed slugger for a 124 wRC+, which would put him among the top 25 hitters in MLB.