UPDATE (11:30 a.m. Sunday): Head coach Brad Stevens confirmed in his pregame news conference that Jae Crowder would start for the Boston Celtics in Game 4, replacing Marcus Smart.

The Boston Celtics have employed the same starting lineup for 21 of their last 23 games, but a shakeup likely is in store for their pivotal Game 4 matchup with the Cleveland Cavaliers.

“When the Celtics opened practice to the media on Saturday, players were stretching to end the session,” ESPN.com’s Chris Forsberg wrote. “Among those in the green practice shirts that typically denote starters were Evan Turner, Avery Bradley, Jae Crowder, Jonas Jerebko, and Tyler Zeller. Marcus Smart and Brandon Bass, who started the first three games of the series, were wearing reserve white.”

Though head coach Brad Stevens would not confirm any lineup changes, Crowder reportedly confirmed to media members that he was planning to start.

“We’re just trying to come hit first,” Crowder said, via ESPN.com.

The Turner-Bradley-Crowder-Jerebko-Zeller lineup was Boston’s most effective Thursday in Game 3, recording a collective plus-10 rating in 15 minutes together. Stevens sent out those five — with Crowder and Jerebko replacing Smart and Bass — to begin the second half in the Celtics’ eventual 103-95 loss.

The Celtics must find some sort of a spark Sunday in Game 4, as another loss would put an end to their season. The Cavaliers won Games 1 and 2 of the first-round playoff series in Cleveland before taking Game 3 at TD Garden.

“I’m excited for everyone (Sunday),” Bradley told reporters. “I think our lineup is different (for Game 4), and I know that we’re just going to go out there and play as hard as we can and play well.”

Forward Jared Sullinger reportedly sat out Saturday’s practice with a bruised tailbone suffered during Thursday’s loss. He is listed as probable for Game 4.

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