Might Serge Ibaka miss Game 6 due to ankle injury?

Serge Ibaka

The Toronto Raptors' depth might be tested in a big way Wednesday.

Raptors big man Serge Ibaka officially is listed as questionable for Game 6 after injuring his left ankle Monday in Game 5 of the team's second-round playoff series with the Boston Celtics.

Ibaka was wearing a walking boot on the ankle Tuesday morning and said he was unsure if he'll be able to play Wednesday with the Raptors facing elimination.

Losing Ibaka would be a tough blow for the Raptors, who rely on the veteran big man for scoring and rim protection off the bench.

Ibaka was quiet offensively Monday night (seven points on 3-for-6 shooting) but hit four 3-pointers in Game 4 to help Toronto earn a series-tying win. He's also averaging 6.6 rebounds and 1.2 blocks per game in the series.

If Ibaka can't go, backups Chris Boucher and Rondae Hollis-Jefferson would be forced to play increased minutes, which could present a mismatch for Celtics big men Daniel Theis and Robert Williams III.

The Theis is right

Celtics' defensive rating vs. Raptors with Theis on the floor

Tip-off for Game 6 is set for 6:30 p.m. ET as the Celtics look to advance to the Eastern Conference Finals for the third time in four years.