Pitta was hurt Saturday, the third day of training camp, when he collided with safety James Ihedigbo in the back of the end zone while going for a pass from Joe Flacco.
He was operated on Saturday night.
"Dennis out for the year," coach John Harbaugh said Sunday. "It's the type of thing that he's not going to be able to come back from this year. There's enough damage in there."
Harbaugh said Baltimore won't know the full extent of Pitta's injury until getting the results of a magnetic resonance imaging (MRI) exam. But this much is certain: Pitta won't be part of the team's effort to win back-to-back titles.
Pitta was one of the centerpieces of the Ravens' offense during their run to a Super Bowl championship last season, and he was expected to take on an even bigger role this season after Baltimore traded top wide receiver Anquan Boldin during the spring.
The 28-year old Pitta, a fourth-round pick of the Ravens in 2010, had 61 catches last year, second on the team behind only Boldin. His seven touchdowns ranked second among receivers behind Torrey Smith.
Pitta also had 14 catches for 163 yards and three touchdowns in Baltimore's four playoff games, including four catches for 26 yards in the Ravens' 34-31 Super Bowl win over the San Francisco 49ers.
Visanthe Shiancoe, a 33-year-old free agent, played in only four games last season with New England. But he played in all 16 games in each of the previous nine seasons — the first four with the New York Giants and the next five with Minnesota.
He has 243 career catches for 2,677 yards and 27 touchdowns.
Shiancoe joined the team for practice Sunday and work Boldin's old number, 81.
More Sports Headlines
Seahawks' Lockette has neck surgery, out for the season Huskies lead the Pac-12 in scoring defense Re-signing Iwakuma a ‘priority’ for Mariners Panthers improve to 7-0, beat Colts 29-26 in OT Volleyball player Firethorne makes transition from high school to college Huskies enter final month with renewed hope for bowl berth Medical personnel were prepared when Lockette was injured Source: 49ers bench Kaepernick, Gabbert to start Sunday
Our new comment system is not supported in IE 7. Please upgrade your browser here.