PITTSBURGH -- Safety Mike Mitchell's four-year run with the Steelers might be up. The Steelers are likely to release Mitchell because of his $8.1 million salary-cap charge but are interested in him returning on a new deal, according to a source.

Releasing Mitchell should save the Steelers around $5 million in cap room, which is necessary for a team that enters the weekend with $1.022 million in space.

A Mitchell departure opens the door for J.J. Wilcox, whom the Steelers recently told they have interest in bringing back, according to a source. The safety, acquired from Tampa Bay in a trade last year, should be in the mix for playing time, though the Steelers would save $3.125 million in cap space if they decided to release him at any point.

The NFL Network first reported the news on Mitchell, who is entering the last season of a five-year, $25 million contract. He has recorded 281 tackles, four interceptions and four forced fumbles as a starter. His lack of splash plays during an injury-riddled 2017 season doesn't help his cause, but he has been a steady starter and good locker-room presence.

Mitchell, 30, is also known for big hits, including takedown attempts on Bengals tight end Tyler Eifert and Chiefs running back Charcandrick West that drew hefty fines. Last season, Mitchell passionately expressed his displeasure for the NFL's targeting rules.

"Just hand us all some flags. Hand us all some flags, and we'll go out there and try to grab the flags off. Because we're not playing football," Mitchell said. "This is not damn football. When I was 6 years old watching Charles Woodson, Rod Woodson, Sean Taylor, the hitters, Jack Tatum -- that's football. This ain't football."

The Steelers have restructured three contracts since February and can create more cap space by reworking veteran deals or releasing players. The Steelers have not informed 33-year-old cornerback William Gay of his status. Releasing Gay would save $1.75 million in space.