The website notes corner Greg Toler was plagued by injuries last season, increasing the urgency for Indy to retain Davis.
Bethea had 108 tackles, two interceptions and six passes defensed last season. It was the fifth time in the last six years he recorded 100-plus tackles.
"He knows he needs to get stronger. He knows that," Grigson said in his postseason press conference.
Grigson did add that he felt Werner got better against the run as the year progressed. Werner started just one game in 2013 and managed 18 tackles and 2 1/2 sacks.
Butler sustained the injury early in the fourth quarter and was unable to return for the remainder of the game. He registered four total tackles (two solo) and one pass defended in a 43-22 defeat.