The Detroit Lions filled a massive void in the running back room, bringing in free agent Isiah Pacheco to replace David Montgomery. Montgomery signed with the Houston Texans, as Detroit ultimately inked star running back Jahmyr Gibbs to a long-term deal. Pacheco was expected to step in as Detroit’s backup behind Gibbs, but has dealt with injuries that have hampered an otherwise promising offseason performance. In the early parts of preseason, the two-time Super Bowl champion was dealing with a nagging injury that raised concerns over his availability for the season opener against the New Orleans Saints. On Thursday, the team revealed the status of Pacheco, who is dealing with a new injury in addition to his knee issue. Lions head coach Dan Campbell was unable to reveal the running back’s status for Week 1, offering insight into a back injury Pacheco recently sustained. Isiah Pacheco now dealing with back injury.Pacheco's prior knee injury is no longer a concern.— Underdog NFL (@UnderdogNFL) August 27, 2026He’ll have just over two weeks to work his way back from injury, with Detroit set to host New Orleans on Sep. 13. If his injury concerns persist, he could face a tumble in fantasy projections coming into the year, currently slotted as RB51 in current ADP rankings, having already fallen four spots in real-time projections. Let’s explore his fantasy outlook in wake of his latest injury update, along with some sleeper candidates that could arise in his absence: Isiah Pacheco’s Fantasy ADP Hampered By Latest Update, Sleepers Arise In Lions BackfieldDetroit Lions running back Sione Vaki (33) practices during training camp at Meijer Performance Center in Allen Park on Monday August 17, 2026. | USA TODAY Network via Reuters ConnectInjuries to the Lions’ running back room could raise several deep-sleeper candidates among the group. Gibbs is the star of the show in Detroit’s offense, and will take on greater volume in 2026, though Detroit’s offense is likely to heavily feature a second running back to offer a change of pace in the run game. Along with Pacheco, former fourth-round pick Sione Vaki is dealing with a back injury that has thrust Jacob Saylors into an expanded role during training camp, making the most of his volume. If these injuries continue to hamper the group entering Week 1, Saylors could step into the RB2 role behind Gibbs, building momentum during the preseason. Vaki is likely to make a return and build on what’s been a solid offseason showing in his own right, presenting a more physical running style than Detroit’s elusive backs. Down the stretch of the season, Pacheco could return to a significant role in the backfield, where he projects to take on plenty of volume near the goal line. These looks will benefit his fantasy outlook over the long term, though his recent injuries are a real concern for fantasy players during draft season. The Lions’ backfield situation will be one worth monitoring as Week 1 of the 2026 season approaches. Read More Fantasy On SI NewsAdd us as a preferred source on GoogleFollow