Plagued by a nagging hamstring injury for much of 2007, Heap played in just six games, recording 23 catches for 239 yards and one touchdown.
Heap led Baltimore in receptions in 2002, 2003 and 2006, and his injury was a major blow to a sputtering offense that ranks 23rd in the NFL.
The Ravens also placed safety Gerome Sapp on injured reserve with a thigh injury on Saturday. Two players were activated from the practice squad: tackle J'Vonne Parker and tight end Jake Nordin.
Baltimore has just two healthy tight ends for Sunday's game against the Pittsburgh Steelers, both undrafted rookies: Nordin and Lee Vickers.
Copyright 2007 by The Associated Press