Jae Crowder spent the first 66 games of the season proving he’s worthy of being an everyday NBA starter. But it has taken his absence over the last three games to prove just how vital he is to the Boston Celtics’ success.

The Celtics have dropped all three contests without their starting swingman by a total of 40 points, the latest coming Friday in a 105-91 loss to the Toronto Raptors. Boston certainly has missed Crowder’s contributions on both ends of the floor, but his absence appears to have had another, more intangible effect on the Celtics: A lack of confidence.

“I think it was more of a factor of being hesitant than it was about not coming out and playing or competing or any of that stuff,” head coach Brad Stevens said in a postgame interview aired on CSN New England. “I don’t know what our players will say, but I think that, for the most part, we looked hesitant. We looked unsure of ourselves.”

That hesitance was most on display early in the fourth quarter. After cutting Toronto’s double-digit lead to five points with a strong third quarter, the Celtics committed six turnovers in the first five minutes of the fourth as part of a 14-2 Raptors run that put the game away. Point guard Isaiah Thomas agreed with his head coach’s assessment.

“We were just being real soft with the ball,” Thomas said on CSN New England. “Not being in control of the possession. And that’s the definition of how we’re playing. We’re not playing to the best of our abilities, we’re not playing like we know how. We’re playing like we’re second-guessing all of our (decisions), whether it’s offensively or defensively. I tried to tell the guys after the game, ‘This is not on the coach, this is not on anybody else. We’re the players, we go out and play, and we’ve got to figure it out.'”

Of course, there are a few explanations for the Celtics’ current “identity crisis.” The first is that Boston has faced stiff competition as their last four losses all have come against playoff contenders. The second is that inexperienced players have been forced to step up without Crowder and Jonas Jerebko, who also missed Friday’s game due to injury: All 13 of Boston’s active players saw the floor Friday, and two of those fourth-quarter turnovers were committed by rookie R.J. Hunter, who has played in less than half of the team’s games this season.

But with just 13 games remaining in their season, the Celtics can’t afford to make excuses, and they’ll need to find a way to get their mojo back if they want to stay in the playoff hunt without Crowder.

“Everybody misses players, right?” Stevens added. “I think (Crowder and Jerebko) are really good players. If they were here tonight, they would have played, but they weren’t, so we need other guys to step up.”

Thumbnail photo Peter Llewellyn/USA TODAY Sports Images

Thumbnail photo via Toronto Raptors guard Cory Joseph (6) dribbles past Boston Celtics guard Terry Rozier (12) in the first second at Air Canada Centre. Raptors beat Celtics 105 - 91.