Doncic already was ruled out for Friday's game against Houston as he nurses the injury. He sprained the same ankle earlier this season before returning to practice 10 days later.
The earliest Doncic could be available is a Feb. 10 home game against Utah. Carlisle said he'd perhaps have an update on Doncic's condition next Saturday.
"Beyond that, there's not much that I can say about the timetable, because one day in, it's really hard to know exactly what the timetable is going to be," Carlisle said prior to Friday's game.
"Once it gets to be two, three or four days, it becomes a little clearer. It's obvious it's a huge loss with a great player and unlucky for it to happen in practice. So we'll go game to game with lineups and try to get the best possible situation to win and go from there."
Doncic was injured during a brief scrimmage at the end of Thursday's practice when he stepped on a teammate's foot while driving to the basket.
Doncic missed four games after the earlier sprain, but it'll be more this time because of the busy NBA schedule.
"Yeah, it's unlucky, but it's the NBA schedule," Carlisle said. "This is just the way it is. We've got to find ways to make it into a positive somehow. Not easy because of the kind of player that he is."
Doncic, 20, who was voted to be an All-Star starter, is averaging 28.8 points, 9.5 rebounds and 8.7 assists per game. He also was selected Friday to participate in the Rising Stars game during All-Star Weekend.
Carlisle said he feels that Doncic will be ready for All-Star Weekend.
"It's just my feeling that he'll be able to participate on some level in those events," Carlisle said. "That's something that's important to us as a franchise. It's important to him. The No. 1 thing that's the most important is that he gets healthy."
The All-Star Game will tip off on Feb. 16, with the Rising Stars game taking place Feb. 14.