Unitas threw a pass one time and jammed his pointer finger into a pass rusher's helmet. Knocked the finger out of the socket. He goes to the sideline and the trainer pops it back in. He's good to go for the next play. 20 years later he couldn't sign autographs because the finger was so arthritic.
Pitta has a little crack in his finger. There are four others on that hand, so why not just use them.