Harbor's addition comes two days after Eric Ebron sustained knee and ankle injuries in a 17-14 loss against Chicago. Ebron was able to finish the game, but was in visible discomfort during and after it.
"Battling life, man," Ebron said after the game. "It's football. It's what you do. You play hurt. You play banged up. It's what we do."
The story said coach Jim Caldwell declined to offer an update on Ebron's status, and it's unclear whether he'll be limited heading into Sunday's game against the Eagles. Harbor is also a former Eagle and is more of an offensive threat than a blocker.