Rondo said doctors told him he will be out "a couple weeks," noting the injury "couldn't have come at a worse time," per Sean Highkin of The Athletic.
Chris B. Haynes of ESPN reported the injury was seen as "pretty serious," and noted the point guard's return will depend on how long the Bulls can extend the season. Nick Friedell of ESPN reported Rondo had a cast on his hand and would be re-evaluated in seven to 10 days.
K.C. Johnson of the Chicago Tribune reported there's nothing definitive, but the team is concerned Rondo's injury could last well into the second round.
When asked if Rondo would return in the playoffs, Bulls head coach Fred Hoiberg told reporters it was "still too early to tell."
Bulls guard Jerian Grant told reporters he would be starting in Rondo's place at point guard.
Rondo struggled during the regular season, averaging just 7.8 points and 6.7 assists per game in his first year with the Bulls. The only positive from his numbers was his 37.6 percent shooting from three-point range, which was the best of his 11-year career.
After spending most of the season coming off the bench, however, the 31-year-old made a more significant impact as a starter in the final month. His play on both ends of the court was instrumental in helping Chicago earn the eighth spot in the playoffs.
Considering the Miami Heat missed out on the postseason on a tiebreaker, every game mattered.
Unfortunately, the Bulls will now likely need to figure out how to play without him, relying on the roster we saw for most of the season when Rondo made a minimal impact.
Jerian Grant and Michael Carter-Williams will be the primary options at point guard in the absence of the four-time All-Star. Although neither is expected to put up big numbers, they each have experience running the offense and could help keep the Bulls competitive. Carter-Williams is also valuable with his work on the defensive end.
Still, everyone on the roster will have to step up if they are going to complete a first-round upset of the Boston Celtics after winning the first two games on the road.