Shipley started five of the 15 games he appeared in for the Colts in 2014, the only season he was with the team. Prior to joining Indianapolis, Shipley spent the 2013 season with the Ravens and started nine games at guard. Shipley also had a previous stint with the Colts in 2012.
Redding, 34, played every game for the Colts last season, recording 35 tackles and 3.5 sacks. Shipley, 28, started four games for Indy last year before ending up as the third-string center.
"Shipley went from starting in Week 1 to losing his starting job, to being inactive, to being the third-string center," the report said. "All without any explanation from coach Chuck Pagano or anybody in the front office."
Shipley, 28, has played in 45 career games, starting 19.
Shipley had been listed as doubtful, while Thornton had previously been ruled out.
Men's Nike Black Arizona Cardinals Glow Logo Performance T-Shirt Shop Now!