Losing key players is part of the game. Every offseason, teams must figure out how to fill the gaps left behind.
Sometimes the answer comes from outside the organization, but often it’s up to someone already on the roster -- whether it's an emerging prospect, a veteran taking on a new role or a player returning from injury -- to step up and carry the load.
The seven players below have become increasingly important as their teams look to replace stars now playing elsewhere.
Moisés Ballesteros, C/DH, Cubs
Signing third baseman Alex Bregman addressed one of the Cubs’ most glaring weaknesses, but that move alone won’t fully offset the loss of Kyle Tucker. The right fielder operates on a different offensive plane than Bregman, and his departure has left Chicago notably thinner in left-handed power. That void has put more of an onus on Ballesteros, MLB Pipeline’s No. 55 prospect. With Seiya Suzuki set to shift back to right field to replace Tucker, Ballesteros could see regular playing time at DH.
Joe Boyle, SP, Rays
The Rays’ trade of Shane Baz in December opened the door for Boyle to earn a spot on Tampa Bay’s starting staff. Given the questions surrounding Shane McClanahan, who is returning from a two-year absence, and free-agent addition Steven Matz, who spent 2025 pitching in relief after several injury-plagued seasons, Boyle’s performance looms large for Tampa Bay. The 6-foot-8 righty has good stuff but will need to overcome his longstanding control problems to stick in the rotation.
Andrés Giménez, SS, Blue Jays
Due to his superior glove, Giménez likely would have become the Blue Jays’ new starting shortstop whether Bo Bichette returned or not. That said, Bichette’s departure has made Giménez’s bat more important. While the addition of third baseman Kazuma Okamoto should help mitigate the loss of Bichette, Toronto also needs Giménez to improve his offensive performance after producing just a 70 wRC+ in 2025.
Marcelo Mayer, 3B, Red Sox
Acquiring first baseman Willson Contreras addressed one infield need for Boston, but the club now has another question across the diamond after Bregman chose the Cubs over a reunion with the Red Sox. Contreras may be capable of replacing Bregman’s offensive production, but Mayer’s performance could determine whether Boston has meaningfully upgraded its infield or merely reshuffled it. Barring a move for another third baseman, the 23-year-old is expected to handle the role at the start of 2026.
Jacob Misiorowski, SP, Brewers
The Brewers’ decision to trade ace Freddy Peralta to the Mets has placed greater responsibility on the arms behind him, perhaps none more so than Misiorowski. The 23-year-old flamethrower endured an uneven rookie season, but given the quality of his stuff, the Brewers will be counting on him to fill one of the top two spots on their starting staff alongside veteran Brandon Woodruff. Woodruff’s injury history only adds to the pressure on Misiorowski to establish himself as a frontline starter.
Joe Musgrove, SP, Padres
The Padres reunited with Michael King in free agency and have Nick Pivetta back after a career year, but Dylan Cease’s exit has left San Diego’s rotation with more questions than answers. In fact, only four clubs are projected to finish with less starting pitching WAR (per FanGraphs) than the Padres in 2026 -- and all four missed the playoffs in ’25. Coming off Tommy John surgery, Musgrove looms as one of the rotation’s biggest swing factors. The 33-year-old owns a 3.20 ERA in a Padres uniform, but he has made just 36 starts in the first three seasons of the five-year, $100 million extension he signed in August ’22.
Andrew Painter, SP, Phillies
Three years after MLB Pipeline ranked him as the top pitching prospect in baseball, Painter still hasn’t appeared in the Majors. The righty appeared to be on a fast track to the big leagues after reaching Double-A as a 19-year-old in 2022, but he sprained his UCL the following spring and eventually underwent Tommy John surgery, missing all of ’24 as well. His MLB debut was further delayed as he struggled in his return to the mound last season. Philadelphia’s rotation depth has allowed the team to weather those setbacks, but Ranger Suárez’s departure as a free agent has made Painter -- now MLB Pipeline's No. 28 overall prospect -- less of a luxury and more of a necessity going into the 2026 campaign.