Why Isiah Pacheco Left Kansas City and What His Back Surgery Means for Detroit
Isiah Pacheco is no longer a Chief. He is a Lion, and he is on the sideline for a different reason than the one fans might expect.
Pacheco signed with Detroit as a free agent before the 2026 season. The Lions brought him in alongside Jahmyr Gibbs to replace the work left behind by David Montgomery, who was traded to the Houston Texans. It was a deliberate reshaping of the running back room. Before Pacheco could make his Detroit debut, training camp went wrong.
He suffered an MCL sprain and a back injury during camp. The Lions placed him on injured reserve with a designation to return on Sept. 1. That move alone guaranteed he would miss at least the first four games of the season, including the Week 1 matchup against the New Orleans Saints. He did not play in that 31-30 overtime win; Gibbs took 29 carries in that game.
Then the situation grew more serious. ESPN reported that Pacheco had surgery to remove a loose body pressing on a nerve in his back, a procedure reported by NFL Network's Ian Rapoport. Recovery is expected to take about 12 weeks, which would put a potential return around early December.
Head coach Dan Campbell was blunt. "It's going to be a while," he said. "It'll be a significant amount of time though."
So the answer to why Pacheco was not playing for the Chiefs against the Broncos in Week 1 is simple: he does not play for the Chiefs anymore. He was not active for the Lions either because of the injured reserve list and the surgery.
The bigger question is why Kansas City let him walk in the first place. The available reporting does not offer a definitive explanation from the Chiefs' front office. What is clear is that Detroit made a significant bet. By trading Montgomery and adding Pacheco, the Lions were trying to build a two-back attack around Gibbs. That plan is now on hold for most of the season.
Gibbs is the clear lead back while Pacheco recovers. The Lions need their depth to hold up. A 12-week absence is not a season-ender, but it is a large chunk of the schedule. The back surgery also raises questions about how much burst Pacheco will have when he returns. He was expected to be a complement to Gibbs, not a replacement. Now Detroit will have to find that complement elsewhere, at least until December.
Pacheco's recovery process will determine whether the Lions get the backfield they planned for in time for a playoff push. If the 12-week timetable holds, he might be ready for the final stretch. Until then, the story is about how Detroit manages without him.