Pitta walked off the field with a trainer less than an hour into Monday's session, the latest -- and easily the most significant -- injury that has marred the first four days of training camp.
"It looks like he broke his hand [and] he'll have to get it repaired in some form or fashion," Ravens coach John Harbaugh said after practice. "[He] should be back for the first regular-season game, but that's very tentative, and I'm a little ahead of myself there."
The Ravens' season opener, a Monday night home game against the Cincinnati Bengals, is six weeks away.
"I shouldn't really say because I really don't know, but it's not going to be that long," said Harbaugh when asked to clarify how long Pitta could be sidelined. "[Tuesday], we could find out it's different because of the MRI so I probably shouldn't have said anything."
Losing Pitta for any length of time would be a significant blow to the Ravens' offense. A good route runner with exceptional hands, Pitta combined with Ed Dickson to form one of the more productive tight end tandems in the NFL last year.
Pitta, a former fourth-round pick who caught only one ball in 2010 while playing behind veteran Todd Heap, made 40 catches for 306 yards and three touchdowns last year. Dickson hauled in 54 passes for 528 yards and five touchdowns. The only other tight end combination that featured two guys with at least 40 receptions each was the New England Patriots' Rob Gronkowski and Aaron Hernandez.
"He's definitely an important part of our offense," said veteran wide receiver Anquan Boldin after he was informed of Pitta's injury. "I think you saw him last year play a big role, especially when it came down the stretch. Dennis is a guy [who] can play inside, a guy [who] we can line up outside, get different mismatches. So, he's a nightmare for defenses across the board. It's a good thing when he's on the field."
Pitta was especially effective in third-down situations. He had 17 catches for 175 yards and two touchdowns on third down. The former BYU standout is one of Flacco's closest friends on the team and their chemistry was evident last season when Pitta became a go-to target in big situations.
In Week 16 against the Bengals, the Ravens opted to regularly line Pitta up on the outside and he took advantage of it with a career-high tying six receptions for a career-high 62 yards and a touchdown as the team clinched the AFC North and a first-round bye.
Pitta was then targeted four times in the Ravens' divisional playoff victory against the Houston Texans and eight times in the AFC championship game loss to the New England Patriots. In the two playoff games, Pitta totaled seven catches for 70 yards.
With Pitta sidelined, the Ravens are left with four healthy tight ends: Dickson, veteran Davon Drew and undrafted rookie free agents Bruce Figgins (Georgia) and Matt Balasavage (Temple).
They are also left with a training room that is filling up by the day. In today's practice alone, four players -- Pitta, starting nose tackle Terrence Cody, reserve linebacker Josh Bynes and undrafted free agent wide receiver Devin Goda -- did not finish the session because of various ailments.
Already without reigning NFL Defensive Player of the Year Terrell Suggs, who could miss the entire season after tearing his Achilles tendon during the offseason, the Ravens' defense is also currently without rookie outside linebacker Courtney Upshaw (bruised shoulder), defensive end Pernell McPhee (knee surgery) and Pro Bowl defensive tackle Haloti Ngata (hamstring).
Harbaugh said that Ngata, who has yet to practice in training camp, is "making strides" but noted that he still has to pass his conditioning test and prove he is "100 percent" healthy. McPhee, currently working on his lateral movement, is "nearing" a return and hasn't yet been ruled out of the Aug. 9 preseason opener.
On the offensive side, wide receivers Tommy Streeter (undisclosed) and Tandon Doss (hamstring) joined David Reed (knee surgery) on the sideline. Tackles Bryant McKinnie (back) Ramon Harewood (foot/ankle) and Jah Reid (calf) also remain out.