(CBS) Amid much speculation about whether he could return in this series from a fractured right thumb and after much effort to be ready to play, Bulls point guard Rajon Rondo is out for a pivotal Game 5 against the Celtics on Wednesday night, he told reporters at morning shootaround.

Rondo on Monday ditched a hard cast on his right hand that also helped immobilize a wrist injury that he suffered late in the regular season, then participated in some of the Bulls’ scrimmage at Tuesday’s practice. He also conducted a private workout later Tuesday after the Bulls arrived in Boston, but not enough progress has been made for him to play in Game 5. Rondo’s late workout Tuesday was focused on conditioning and shooting floaters with his left hand, the Tribune’s K.C. Johnson reported.

Rondo hasn’t ruled out a return for Game 6 on Friday, though he hasn’t indicated it’s likely either. He suffered the fractured thumb in a Game 2 loss on April 18 and said a few days afterward that doctors told him he’d be out “a couple weeks.”

The first-round series is tied 2-2. Rondo averaged 11.5 points, 8.5 rebounds and 10 assists in the first two games, a pair of Bulls wins that he spearheaded with his quality play and knack for controlling the pace.

Isaiah Canaan will start Game 5 in Rondo’s place after young Bulls point guards Jerian Grant and Michael Carter-Williams have struggled in the series.

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