The Patriots tight end reportedly threatened retirement upon the Lions and Patriots almost completing a blockbuster trade for him last spring, sources told ESPN.
Ahead of the 2018 season, the Patriots' reworked Gronkowski's contract, adding $4.3 million in incentives, including $1 million per-game roster bonuses.
Wide receiver Josh Gordon is inactive for tonight's game.
Here is the full list of Patriots inactives: Gordon, tight end Jacob Hollister, safety Patrick Chung, defensive end Trey Flowers, cornerback Eric Rowe, and offensive linemen Brian Schwenke and Cole Croston. He was limited all week in practice with a hamstring injury, and had officially been listed as questionable, giving him 50-50 odds of playing.
J.C. Jackson, Keion Crossen and Derek Rivers are all active and will be making their National Football League debuts.
Gronkowski led the Patriots with 1,084 yards and eight touchdowns previous year across 14 games.
Amusing enough, the Patriots play against the Lions on Sunday Night Football in a game that marks the first time Matt Patricia will be coaching against his former team.
New England hopes to bounce back from last week's loss to the Jacksonville Jaguars.