What happened: Miami signed edge rusher Amari Gainer to the practice squad and released defensive lineman Keith Cooper Jr. The transaction reunites Gainer with the developmental unit two days after the Dolphins released him to make room for Eric Watts.

Why it matters: The rapid turnaround restores depth on the defensive front after a series of early-week roster adjustments. Cooper's departure creates the necessary vacancy after he previously cleared waivers in late September.

What to watch: The organization will continue to evaluate its practice squad combinations throughout the regular season.