Calvin Johnson shows off gory finger injury (it's not for weak stomachs)

Calvin Johnson messed up his finger in the 2013 season to the point it wouldn't bend normally. He had surgery on it and then wore a protective splint the following season in an attempt to keep it straight.

None of it made a difference in the now-retired Detroit Lions receiver's career -- but it was one of the many ailments he picked up. It was always visible when you saw him and shook his hand, but you could never really see it up close.

Until now.

Johnson posted a picture not only of the finger, but of part of the surgery he had to fix the finger back then, on Instagram early Friday morning and it's nasty. Really, really nasty.

The picture is definitely one way to start your weekend.

Johnson posted the picture after his former rival, Charles Tillman, posted his own picture of a nasty finger injury suffered in his career. The two battled often -- and it was one of the best rivalries in the NFC North.

Just finished a set of push-ups...was I doing it right? #KeepPounding #VladsGym

A photo posted by Charles Tillman (@peanuttillman) on

Johnson still managed three straight 1,000-yard seasons with the messed up digit, including a 1,492-yard season in 2013, a 1,077-yard season in 2014 and a 1,214-yard season in his final year last season.