Although the former Pro Bowl selection expressed confidence that he would be able to take part in practice on a full-time basis next month and will be ready for training camp, he's currently behind schedule in his rehabilitation.

"There are some issues with the lower back that he's got to work through, strengthen and heal," Ravens coach John Harbaugh said Tuesday. "He's not as far along as we all thought he would be and he thought he would be, so we're just trying to work through it."

Heap registered just 35 receptions last season.

He's being extra cautious about not rushing back too soon and aggravating his back again.

"I'm trying to get a few little things to get back out there playing full speed," Heap said. "It's mostly just lower back, the same stuff I was dealing with at the end of last year. I'm working into it right now.

"I have been doing individual drills every day, just making sure that I'm completely healthy before I get back out there, so I don't take a step backward. It's time to get better and make sure that your body is ready to go."

INJURY REPORT: Wide receiver Demetrius Williams had his upper leg wrapped up toward the end of practice.

He's coming off Achilles' tendon surgery, ending last season on injured reserve.

"He's been so concentrated on getting the Achilles' thing worked out that he hasn't been able to do the kind of running that kind of athlete needs to do to have everything else in shape," Harbaugh said. "There are going to be groins, hip flexors, hamstrings, calves that are going to come up and you're going to have to push through it, but not overdo it."

Williams said that he isn't concerned about the slow pace of recovery.

"I've worked the ankle so long, and we just don't want to reinjure it," Williams said. "I know myself and right now I'm not running the way I'm supposed to be. You have to be careful with it."

Also still dealing with injuries: wide receivers Derrick Mason (shoulder) and Mark Clayton (heel), running back Willis McGahee (knee), tight ends L.J. Smith (groin) and Quinn Sypniewski (knee), offensive tackles Oniel Cousins (torn left pectoral) and Adam Terry (knee surgery), defensive tackle Kelly Talavou (shoulder), linebackers Antwan Barnes (pectoral surgery) and Jason Phillips (meniscus) and cornerbacks Samari Rolle (groin), Chris Carr (shoulder), Fabian Washington (neck/shoulder) and Frank Walker (shoulder).

"Derrick's program right now is geared toward the mental part of football, the rehab, the lifting and conditioning," Harbaugh said. "If he was fully healthy, he'd be out here."

Clayton indicated that his heel ailment, plantar fasciitis, isn't serious.

"It's getting better," Clayton said. "It's not that bad."

SURPRISED: The Ravens weren't expecting veteran offensive tackle Willie Anderson to retire last week due to chronic knee and foot issues.

A four-time Pro Bowl selection, Anderson played one season for Baltimore after spending the previous dozen years with the Cincinnati Bengals.

"I probably was surprised that it was a retirement announcement, that it started going that way because Willie is a competitor and he would not want to not play football this year," Harbaugh said. "He talked to us about the fact that he would work out and then he would be jacked up with his knee and his foot for the next two or three days. So, it's hard for him to get the kind of conditioning, the kind of shape that he wants to get in to be the kind of player he has been accustomed to being over the years."

VYING FOR NO. 3: Newly-signed veteran Kelley Washington could create a niche as a third wide receiver candidate as well as operating on special teams.

"You don't want to ever put limitations on a guy," Harbaugh said. "One good thing about him is he doesn't have a lot of wear and tear on his body. He's kind of a young 29. We have some high hopes for Kelley, and that's why we signed him."

QUICK HITS: Harbaugh was impressed with the high attendance at a voluntary camp. "Obviously, it's exciting, the fact that guys want to be here, but it's not surprising," he said. "Our players love football. There will be situations when guys can't be here, too. They've got things coming up in their life." ... Washington's one-year contract is for the veteran minimum with no signing bonus, according to his agent. ... Starting defensive tackle Haloti Ngata wasn't at practice as well as outside linebacker Terrell Suggs, the Ravens' unsigned franchise player. ... Harbaugh has been in touch with Philadelphia Eagles defensive coordinator Jim Johnson, who has taken a leave of absence while undergoing a new round of chemotherapy to treat melanoma skin cancer. "Jim is a fighter," Harbaugh said. "Jim has great spirit. Jim's going to fight and my guess is he's going to beat this. Jim Johnson is one of the most tremendous competitors and toughest human beings I've ever met in my life. My guess is he's going to be coaching in training camp." ... Cornerback Anwar Phillips blocked rookie kicker Graham Gano's field goal attempt. ... Wide receiver Yamon Figurs caught a touchdown pass. ... With McGahee not practicing, Ray Rice and Cedric Peerman turned in strong performances. ... Cornerback Domonique Foxworth intercepted a Troy Smith pass.