Pitta is expected to miss the entire preseason, but Harbaugh added that the team hopes to have Pitta back for the team's September 10 season-opener against the Cincinnati Bengals.
Though Pitta is the No. 2 tight end behind Ed Dickson, the Ravens frequently use two-tight end personnel groupings and do not have a great deal of depth behind Dickson and Pitta to lose either player for a signnificant stretch of action.
Davon Drew, a 2009 fifth-round draft pick, and undrafted rookies Matt Balsavage and Bruce Figgins are the other tight ends on the roster, but it would not be a surprise if the Ravens looked to add a veteran free agent to help during camp and the preseason.
A 2010 fourth-round pick out of BYU, Pitta started a pair of games and played in nearly 52 percent of the Ravens' offensive snaps (Dickson played in 86.9 percent of the snaps) in 2011. After catching one pass for one yard as a rookie, Pitta caught 40 passes for 405 yards and three touchdowns last season.