Head coach Steve Nash described the 29-year-old as having "some miles to make up" in his recovery from an ankle injury. Should the Nets defeat the Bucks and advance to the Eastern Conference Semifinals, though, Nash expects Irving to be back at some point.
"It is not a season-threatening situation," Nash said.
Irving sat out Brooklyn's Game 5 win over the Bucks after spraining his ankle in the second quarter of Game 4 on Tuesday.
The Nets officially announced the issue as a right ankle sprain. They didn't put a timetable on his return, but they did rule him out of Thursday's Game 6 against the Bucks to continue receiving treatment.
Brooklyn erased a 17-point deficit in Game 5 against Milwaukee thanks to a classic performance from Kevin Durant. The former NBA MVP put up 49 points, 17 rebounds and 10 assists in 48 minutes to help the Nets take a 3-2 series lead.
Durant had another strong showing in Game 6, putting up 32 points and 11 rebounds in 40 minutes of action. However, behind Khris Middleton (38 points) and Giannis Antetokounmpo (30), Milwaukee was able to even the series and force a winner-take-all game on Saturday.
Irving missed 18 games during the regular season because of injuries and rest. But the seven-time All-Star was terrific when he did play, averaging 26.9 points on 50.6 percent shooting in 54 starts.
Until Irving can return to the lineup, Nash will likely have to continue elevating one of Bruce Brown or Jeff Green to the starting lineup.