Chicago Bulls guard Rajon Rondo could play through a significant injury once again.

Rondo took steps Tuesday night to return from a fractured right thumb and attempt to play in Game 5 of the Bulls’ first-round series against the Boston Celtics, league sources told The Vertical. Around Rondo and the Bulls, there’s belief that the four-time All-Star has a chance to return but a final determination has not been made, league sources said.

Rondo helped the Bulls to a 2-0 series lead over Boston, but suffered the broken thumb during Game 2 and missed two consecutive losses that evened the series.

Rondo averaged 11.5 points, 10 assists, 8.5 rebounds and 3.5 steals in the first two games of the series, providing leadership and rejuvenating a 41-41 No. 8 seed with his postseason experience and production.

Rondo received a two-week timetable to return from doctors last Friday, but one source described his desire to play as “guts and determination.” He replaced his cast with a thumb splint on Monday and shot jumpers and dribbled with both hands Tuesday. Bulls coach Fred Hoiberg had originally ruled Rondo out of Game 5 on Tuesday afternoon.

Rondo has a history of persevering despite serious injuries, playing through a dislocated elbow in a playoff game in 2011 and playing a few minutes after tearing the ACL in his right knee in a 2013 regular-season game.

Rondo, 31, averaged 7.8 points, 6.7 assists and 5.1 rebounds in 69 games this season. Chicago narrowly made the playoffs but has pushed toward a possible upset of the No. 1 seed in the Eastern Conference.

Without Rondo, the Bulls have lacked reliable point-guard play and have turned to Isaiah Canaan as a potential starter in Game 5.

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