The Lions designated Thomas (forearm) to return from injured reserve Monday, per the NFL's transaction log.
Nolan Bianchi of The Detroit News initially reported that Thomas would be designated to return from IR on Tuesday, but the Lions have opted to open the 2020 fifth-rounder's 21-day practice window a day earlier. Thomas is in the final stages of his recovery from a broken forearm that he sustained in late September, and his practice participation this week will determine whether he's activated off IR ahead of the Lions' NFC North tilt against the Vikings on Sunday.