Keiser had 4.5 sacks and 20 tackles in 12 games last season.
"He's a great route runner. He's excellent in terms of vision and the ability to catch and the ability to cut. He's very serviceable as a pass blocker. He can stay in and be an every-down back, which a lot of teams don't do nowadays."
Five-time Pro Bowl linebacker
Harrison had been scheduled to take a physical with the
"I have made a difficult decision to retire as of today," Harrison wrote. "My love for family and the need to be there for them outweighs my desire to play the game."
Harrison went on to thank the Steelers and Bengals organization for whom he played.