WALTHAM, Mass. -- Even while working his way back from ACL surgery, Rajon Rondo has been a consistent presence for the Celtics at practices, shootarounds and games this season. He missed Tuesday's workout for what coach Brad Stevens said was a check-up on his surgically repaired knee, but there's a buzz growing as Rondo navigates the final stages of rehab.

Rondo appears to be ramping up his pregame workouts. During the team's recently completed two-game road trip, he was seen running sprints on the sideline and playing 1-on-1 with teammate MarShon Brooks. So how does Rondo look to his sparring partner?

"He looks good, man," Brooks said after Tuesday's practice at HealthPoint. "He’s quick. He’s very quick, always been quick. I think he’s almost there."

While both the Celtics and Rondo have backed off any firm timelines during his rehab, a December return often has been hinted. Stevens and president of basketball operations Danny Ainge have stressed that Rondo's return is not imminent, but his teammates depict a player who is chomping at the bit to get back on the court -- even as they caution him to take his time to ensure he's ready both mentally and physically.

"It’s good to see him on the court working out every now and then," backcourt mate Avery Bradley said. "I just can’t wait until he gets back. It’s fun to see him out there. He wants to be back so bad. He’s getting closer out there."

Jared Sullinger, who underwent season-ending back surgery in February and worked hard to get back on the floor this season, knows that Rondo must be anxious. He likes what he sees from him on the floor as he works his way back.

"[Rondo] still has his quickness," Sullinger said. "He can still finish with either hand. He’s still crafty with the basketball. Rondo is Rondo. Once that knee gets 100 percent, look out. He’s going to be back full effect."

Echoed Gerald Wallace: "[Rondo is] moving better. And obviously, just from hearing him talk, his confidence is a lot better in his leg. And he’s feeling a lot better about himself out on the court. We don’t want him to rush it. We don’t want him to come back mentally not prepared. ... When he’s ready, he’ll be back."

Stevens previously noted that the team has integrated Rondo into skeleton offense work. But he cautioned against reading too much into that.

"When we do that stuff, even if it’s 100 percent [effort], there are no other bodies on the court, so you can’t tell [how close he is to returning]," Stevens said. "I know he’s playing a little bit of 1-on-1 before games, but I’m not out there so I haven’t seen a whole lot that would say he’d be close to ready or whatever the case may be. I have not gotten any word that we have a timeline that is anytime in the very, very near future."

Ainge noted recently that Rondo will visit with operating surgeon Dr. James Andrew in Florida to check the stability of the knee and could be cleared for contact soon after, which would allow him to return to full practice activities with the team.