Celtics point guard Kyrie Irving suffered a minor facial fracture when he took an inadvertent elbow to the head from teammate Aron Baynes during Friday night’s comeback win over the Hornets and is doubtful to play against the Raptors on Sunday, according to the team.
The incident occurred just two minutes into the game, when Baynes landed after attempting to block Kemba Walker’s shot. Irving was bleeding and had to be helped off the court, and he left the arena at halftime. The Celtics said he would be monitored for concussion-like symptoms.
Center Al Horford, meanwhile, has progressed after suffering a concussion last Monday and is listed as probable to play against Toronto.
With or without Irving and Horford, Sunday’s game figures to be one of Boston’s bigger tests of this stretch. The Raptors returned their core from last season’s 51-win team. Last year they went 3-1 against the Celtics, the loss coming when All-Star DeMar DeRozan did not play.
“It should be a fun one,’’ guard Terry Rozier said. “We’re going to be ready. We’re going to play Celtics basketball. We’re just going to do what we do no matter who we got. No matter who we’re going to play with, we’re going to play hard.’’
Defense is locked in
The Celtics completed another precise defensive performance Friday night as they charged back from an 18-point third-quarter deficit by swarming and stymieing Charlotte in the second half, when the Hornets made just 28.2 percent of their shots and committed 11 turnovers.
For the Celtics, it was the latest and perhaps most impressive stretch of this season that has thus far been full of them.
“Our defense, you know, went up to a different level in the third and fourth quarters,’’ coach Brad Stevens said. “They really competed at a high level.’’
Through 13 games the Celtics have a 94.8 defensive rating, meaning they are allowing 94.8 points per 100 possessions. That is 3.9 points fewer than the next closest team, the Thunder. To put that massive gap in perspective, the Thunder are just 4.5 points better than the 16th-ranked defensive team, the Bulls.
The Celtics’ impenetrable defense is probably not sustainable, but one-sixth of the season is now complete, so the dominant start cannot be discounted. No team has finished a season with a defensive rating of 94.8 or better since 2003-04, when the Spurs, Pistons, and Pacers all did.
“We have a lot of fight,’’ forward Marcus Morris said. “Tenacity is high, defense is high. We’ve been doing a great job on defense and Brad Stevens, he’s a guru. He’s putting us in the right spots, calling out the plays and doing really good just utilizing everyone in different positions.’’
The Celtics have now held five opponents to fewer than 90 points. Last season they hit that mark just six times.
Howard plays the villain
With 7:45 left in the second quarter on Friday, Charlotte’s Dwight Howard and Celtics guard Marcus Smart were tussling on a box-out when Howard took Smart down with a forearm. Smart jumped to his feet and confronted Howard before the two were separated. After a video review, Howard was called for a technical foul.
The play energized the crowd, which showered Howard with catcalls during the review. Howard egged them on by smiling and motioning with his hands for them to get louder.
“It’s basketball — the fans and entertaining,’’ Howard said after the game. “I’ve fought a lot of battles here, in Boston, since my time in the NBA. Some good wins and some bad losses. But it’s a part of life. It’s always fun to play here in the Garden.’’
“Like I said, I have so many memories. So no matter what, if they boo me, say I suck, it will always be a fun place to play.’’
Later in the quarter the Celtics began to intentionally foul Howard to send him to the free throw line, and he missed four foul shots in a row. Howard totaled 6 points, 11 boards, and 7 turnovers.
Adam Himmelsbach can be reached at adam.himmelsbach@globe.com.
