The Buffalo Bills have long relied on a powerful running game, anchored by standout running back James Cook. However, With the departure of key fullback Reggie Gilliam to the New England Patriots in free agency, the team faced a noticeable gap in their offensive lineup.
Enter Jackson Acker, an undrafted free agent out of Wisconsin, whose arrival appears perfectly timed to fill that void and potentially step into a starting role right away.
Acker, a 6-foot-1, 247-pound fullback, brings a physical, blue-collar style that mirrors Gilliam’s contributions. Both players entered the league as undrafted prospects, and their physical profiles are strikingly similar, with Acker just a few pounds lighter.
During his time with the Badgers, Acker often operated in the shadows as a lead blocker for a multi-headed rushing attack. Yet his late-season opportunities highlighted his reliability, particularly in short-yardage and conversion situations where he converted every third- and fourth-down carry into a first down.
He finished his final college campaign with modest but meaningful stats: 55 rushing yards on 15 carries and eight receptions for 66 yards plus a touchdown.
Bleacher Report analyst Gary Davenport sees significant potential in Acker making the 53-man roster and contributing early, going as far to claim he could start Week 1.
“Yes, the NFL still has fullbacks — at least a few. James Cook had a career year for the Bills in 2025, leading the league with 1,621 rushing yards,” Davenport wrote. “Some of the credit for that massive season belongs to Reggie Gilliam, who was Cook’s lead blocker. But Gilliam joined the rival Patriots in free agency, creating a hole at fullback the Bills addressed by signing Wisconsin’s Jackson Acker after the draft.
“As things stand, the only other fullback in Buffalo is converted linebacker Ben VanSumeren, who has limited offensive potential but is a special teams ace. Acker will also have to show he can play well on special teams, but if the 6’1″ 247-pounder can pull that off, he could do more than just make the roster. He could even be Buffalo’s Week 1 starter at fullback.”
VanSumeren represents a less ideal option for the fullback spot given his background as a linebacker and his recovery from a torn ACL sustained early in the previous season. This situation elevates Acker’s opportunity, especially if he can prove himself on special teams while delivering in the run game.
Analysts took notice of Acker shortly after his signing in April, when the Bills brought him in with a modest guaranteed portion of his contract.
Observers quickly pointed out his potential to replace Gilliam’s gritty blocking role, which had been instrumental in opening lanes for Cook’s league-leading season. Acker’s willingness to handle the tough, under-the-radar duties could make him a seamless fit in Buffalo’s scheme as they prepare for their season opener against the Houston Texans.
While training camp and preseason will ultimately decide his fate, the early buzz around Acker suggests the Bills may have uncovered a hidden gem.
In a league where fullbacks are increasingly rare, his blend of size, blocking prowess, and dependability in critical moments could allow him to carve out a meaningful role on a contending roster. If he capitalizes on this chance, Jackson Acker could go from undrafted long shot to Week 1 starter in short order.
