Billups, who initially suffered the injury March 19 against the Sacramento Kings, had been limited to shooting and non-contact drills, but participated in full-court drills and 5-on-5 scrimmages Tuesday.
Del Negro said he wasn't sure if Billups would play Wednesday night against the Minnesota Timberwolves, but said Billups will likely return before the regular season ends April 17.
"It's all about how he feels tomorrow," Del Negro said. "He looked pretty good. We didn't go long today, but we went pretty hard for 30 or 40 minutes. He looked good."
The Clippers practiced with a full roster for one of the first times all season, as Del Negro confirmed that all 15 players participated. Still, Del Negro wouldn't speculate as to when Billups would return.
With Billups, a career 38.8 percent 3-point shooter and steady ball-handler with playoff experience, constantly in and out of the lineup, the Clippers have had to make adjustments on a game-to-game basis.
"You'd love to have everybody play a little bit and get that rhythm and that feel back," Blake Griffin said after practice Tuesday. "But I said this when we were waiting for him to come back from his Achilles [injury], he's the least of my worries when it comes to somebody who's going to come in and contribute. Whether he's scoring or not, his presence out there is an advantage for us."
Whether he returns before the regular season ends or when the playoffs begin, his teammates are confident he will fit in seamlessly.
"It's an adjustment, but I think with Chauncey because of his knowledge of the game ... when he comes back, it's like he never missed a beat," Chris Paul said after practice.
Billups, 36, has played only 20 games this season, averaging 8.2 points and 2.2 assists. He has battled an assortment of injuries, but the Clippers remain optimistic he will contribute as a key role player throughout the playoffs.
"Chauncey brings a whole different dynamic to our team," Paul said. "The way he shoots the ball in the game, foul shooting, ball handling, and everybody around the league fears Chauncey, to a certain extent, because he's not afraid to make and take big shots.