Neal signed a one-year deal with the Dolphins on Wednesday, Cameron Wolfe of NFL Network reports.
Neal was released by the Bills on Wednesday.
Neal (ankle) did not practice Wednesday.
Neal re-signed for three years Wednesday, the Bills' official site reports.
Neal was not listed on the Bills injury report Wednesday.
Neal exited Sunday's game against the Dolphins to be evaluated for a head injury.
Neal was activated off the reserve/COVID-19 list Wednesday, Maddy Glab of the Bills' official site reports.
Neal is one of five Bills that have been placed on the Reserve/COVID-19 list, Sal Maiorana of the Rochester Democrat and Chronicle reports.
Neal practiced fully all week and has been cleared from the concussion protocol, The Buffalo News reports.
Neal, who missed Sunday's game due to a concussion suffered in Week 11, was listed as a full participant on Monday's estimated practice report.