Pats OT Sebastian Vollmer practices

TAMPA, Fla. -- Offensive tackle Sebastian Vollmer was among a handful of previously injured players who returned to practice Wednesday, as the New England Patriots held the first of two joint sessions with the Tampa Bay Buccaneers.

The practices are being held in advance of Friday's preseason game between the teams at Raymond James Stadium.

Given some of the struggles of the team's offensive tackles in the first two preseason games, Vollmer's presence is welcome. He was inserted immediately into the first unit at right tackle in place of second-year man Marcus Cannon during the warm-up part of Wednesday's practice.

Vollmer, who was limited in 2011 with back and foot injuries, had opened camp on the physically unable to perform list.

"It feels good to get some stuff done," he said, relaying that he didn't participate in team drills Wednesday but was part of 1-on-1s. "It's humid, but luckily it's not as hot."

Vollmer said he will follow the advice of the medical staff in terms of how much more he might do in Thursday's practice, which presumably won't be in full pads.

In addition, he set no timetable on if he will be ready to play in the season opener Sept. 9 at Tennessee.

"I have no idea. I'm obviously making progress, working as hard as I can, and if i'm ready, I'm ready. If I'm not, I'm not," he said. "I'm obviously hoping so and doing whatever I can to do it."

Offensive line coach Dante Scarnecchia defended the progress of left tackle Nate Solder and Cannon, who both have had struggles in training camp and preseason games.

"Personally, I'm really pleased with the way (Solder and Cannon) are developing. Is it the finished product? No. We have a couple more weeks to get it as good as it can be, and then we're going to play games."

In addition to Vollmer, tight end Daniel Fells -- who also opened training camp on the PUP list -- was on the field for practice.

So too were fullback Spencer Larsen (missed last 12 practices with unknown injury) and rookie cornerback Alfonzo Dennard (missed last 16 practices with a hamstring injury).

Rookie running back Jeff Demps also was on the field for the full-pads practice. He might be a world-class sprinter, having won a silver medal at the Olympics, but that hasn't made his transition back to football a cinch.

"That's probably going to be the toughest part, just getting back into that football shape," Demps told reporters after the joint practice that lasted 2 hours and 45 minutes.

Demps added that learning the Patriots' plays will also be a challenge -- he does have some background in the team's system from having played for former New England offensive coordinator Charlie Weis at Florida -- but the coaching staff didn't hesitate to throw him right into the mix Wednesday.

Wearing jersey No. 42, he competed in 1-on-1 blitz pickup drills against Buccaneers players. His effort was described as "courageous" by running backs coach Ivan Fears.

Demps is listed at 5-foot-7 on the team's roster, and said he was 183 pounds, five pounds lighter than his playing weight at Florida.

Earlier in practice, he was also seen fielding kickoffs, which is one area that the Patriots figure to give Demps a chance to shine.

Injured players not spotted included safety Patrick Chung (shoulder), wide receiver Jabar Gaffney (leg), linebacker Tracy White (leg), offensive tackle Matt Kopa (ankle), tight end Visanthe Shiancoe (hamstring) and defensive lineman Gerard Warren (unknown).

Media members watched the first 30 minutes of practice before departing, per Buccaneers team policy.