ASHBURN, Va. — When the Washington Commanders broke for the offseason and awaited the fallout from their 5-12 season, coach Dan Quinn gave his running back — the only running back under contract for 2026 at the time — a to-do list.He needed to add size, both for strength and for reserve during the long NFL season.He needed to improve his ball security after losing two of the team’s five rushing fumbles last season.And he needed to expand his game.“I do feel like there’s like this elevation that’s taking place with him,” Quinn said at the start of minicamp last week. “He’s always been hungry for it.”Jacory Croskey-Merritt, the second-year back known to most anyone simply as “Bill,” participated in only two offseason practices open to the media because of a minor hamstring issue, but he revealed plenty as the team’s new offense starts to take shape.Croskey-Merritt is significantly bigger, which he attributed to a cleaner diet and more time in the weight room. While his size was the most noticeable change, it was only a small part of his broader plan to be “a whole different version” of himself.And the Commanders will need it.Minicamp takeaways: Commanders have built their foundationNicki JhabvalaAs Washington shifts to a system that features the quarterback under center more often and uses a heavier dose of outside zone runs, Croskey-Merritt has to quickly evolve his game to be a more complete back — one who can reliably block and be a target in the pass game, who can be used in motion (often) and who can create the same explosiveness on a variety of runs from a variety of alignments.“From a play design, a little bit different with some stretch cutback-type of plays,” Quinn said. “So, seeing him do that, his explosiveness to go and do that, that’s a big deal.”Washington remade its running backs room this offseason by adding veterans Rachaad White, a former college teammate of quarterback Jayden Daniels, and Jerome Ford. The team also re-signed veteran Jeremy McNichols, selected Penn State’s Kaytron Allen in the sixth round of the draft and signed undrafted rookie Robert Henry Jr. out of the University of Texas at San Antonio.On paper, the group has speed and a variety of skill sets. But it’s perhaps the most open of any position heading into training camp for the Commanders. It has no obvious leader; none of the team’s six backs have topped 1,000 rushing yards in a season, and, despite Croskey-Merritt’s impressive first year in which he totaled 805 rushing yards and earned the NFL’s rookie of the week honor four times, he’s still a developing player.But that may not be indicative of a shortcoming. In fact, it may all be part of the plan — one that, of course, succeeds if Croskey-Merritt can develop into the player the Commanders envision.