The 275-pound Klecko has played defensive tackle and special teams and served as a short-yardage fullback for the New England Patriots and Indianapolis Colts. The Eagles will use Klecko as a full-time fullback.
"Everything I've ever done at fullback has been very raw," Klecko said. "This is going to be a whole learning experience."
Klecko said he will need to lose about 20 pounds to play fullback.
"I have to come to camp thinking I don't have a job," he said. "I have to work for it."
In 47 games, Klecko has 39 tackles and three sacks and has caught four passes for 20 yards and a touchdown. He also had a touchdown catch in the Colts' 2007 AFC Championship Game win over the Patriots.
A native of nearby Marlboro, N.J., Klecko played at Temple and was a fourth-round pick by the Patriots in the 2003 draft.