Alexander Mattison’s neck injury in the preseason opener sidelined him for the 2025 season and landed him on injured reserve after surgery in Chicago. He carried eight yards and a touchdown on three rushing attempts before the injury, and Miami had pegged him as the primary power back to pair with De'Von Achane’s speed and Jaylen Wright’s depth. In response, the Dolphins added Mike Boone and Aaron Shampklin to bolster the backfield behind Achane, Gordon II, Wright, and the rest of the group.

Mattison’s exit opens a clear path for Ollie Gordon II, who topped Miami’s rushing ledger in the weekend’s play with 33 yards and a touchdown on eight carries. The sixth-round pick may be thrust into a larger role as the Dolphins navigate a crowded backfield, while Boone and Shampklin provide veteran and special-teams depth. Fantasy managers should monitor Gordon II’s opportunity window as the backfield reconstitutes itself.

Bottom line: Miami’s backfield now leans into a deeper, more committee-like approach, with Gordon II offering upside as the rookie seizes a glow of opportunity. The team’s week-to-week plan will hinge on how the new signings integrate and how Gordon II handles increased exposure behind Achane and Wright.