The Boston Celtics boast one of the NBA’s most fearsome starting lineups when at full strength. Oddly enough, the group’s undeniable talent hasn’t translated to success on their quest for a repeat.

Boston is 5-5 this season with its “preferred” starting lineup of Jrue Holiday, Derrick White, Jaylen Brown, Jayson Tatum, and Kristaps Porzingis. With that lineup Wednesday in Toronto, the Celtics were thoroughly outplayed on both ends of the court en route to a resounding 110-97 loss.

Porzingis was a bright spot for the C’s with 18 points on 7-of-11 shooting (4-5 3-PT). The Non-Porzingis starters, however, shot a combined 16-for-51 (31.4 percent) from the floor. Payton Pritchard was the only other Celtic in double figures with a team-high 20 points off the bench.

After Wednesday’s head-scratching loss, NBC Sports Boston’s Celtics analyst Brian Scalabrine suggested it may be time for coach Joe Mazzulla to make some lineup adjustments.

“Joe Mazzulla might have to make a tough decision right here,” Scalabrine said, as seen in the video player above. ” ‘You know what? I’ve got a lot of dogs on this bench, I’m just gonna go with the guys who are playing the hardest. I’m just gonna go with maybe the ‘Stay Ready Group’ or Pritchard, (Sam) Hauser, you can throw (Luke) Kornet in there, Al Horford.’ If those guys are making an impact, you just have to go with those guys.”

It isn’t unusual for defending champions to go through the motions midway through the season. It probably isn’t a coincidence that Porzingis, who missed a chunk of the season recovering from injury, and Pritchard, who consistently makes the most of his minutes off the bench, showed the most effort in Wednesday’s defeat. As for the everyday starters, perhaps they’re struggling to fend off the “wake us up for the playoffs” mindset.

Scalabrine believes Mazzulla and the C’s could benefit from prioritizing effort over talent while they work out their issues.

“I wonder at what point does Joe say, ‘All right, if we’re not gonna play with that edge, I’m just gonna go with the guy who’s gonna play with that edge.’ That’s a hard thing to do when you’ve got a team like we have. It’s almost as if we have too many good players,” Scalabrine added.

“Think about it: When we’re healthy and whole, we’re not good. We don’t play as hard, and you would think, ‘I have guys behind me champing at the bit to get in, we have all this depth.’ But when we’re whole, it feels like we think, ‘We’re healthy now and we’re gonna win.’ Because that’s what the NBA does. When you’re unhealthy, ‘Oh, we’re unhealthy, that’s why we lose.’ Well, when you’re healthy, do you think all of a sudden you can just show up and go out there and play and just get it? It doesn’t work like that.

“… Maybe it’s just like, Joe’s gonna start saying, ‘Listen, I’m just gonna go with the dudes that are getting it done and whatever that is, that’s what we’re gonna go with.’ ”

The Celtics are 7-7 over their last 14 games with three double-digit losses in their last five. They didn’t lose by 10 or more points in their first 35 games this season.

Boston will look to get back on track Friday when it welcomes the Orlando Magic to TD Garden. Tip-off is set for 7 p.m. ET on NBC Sports Boston.