Spoelstra’s big decision for Heat and the eyebrow-raising Tatum/Highsmith matchup numbers

Since losing Tyler Herro and Victor Oladipo to injuries early in the playoffs, and since reinserting Kevin Love in the starting lineup in Game 3 of that first-round series against Milwaukee, Heat coach Erik Spoelstra hasn’t had any difficult lineup decisions for four weeks of this playoff run.

That changes now.

Haywood Highsmith’s strong work in Thursday’s Game 5 loss – coupled with Kevin Love’s speed deficit against a smaller Boston lineup — leaves Spoelstra with four options for Game 6 on Saturday at Kaseya Center (8:30 p.m., TNT):

▪ Start Highsmith ahead of Love and replace Cody Zeller with Love as the Heat’s backup center.

▪ Start Highsmith ahead of Love, stick with Zeller at backup center and don’t play Love at all.

▪ Stick with Love in the starting lineup but find a role for Highsmith off the bench.

▪ Start Caleb Martin, who has been arguably the Heat’s best player in the series. Spoelstra seems inclined to continue playing Martin off the bench.

Spoelstra declined to say whether he would insert Highsmith in the starting group of Game 6, after opening the second half of Game 5 with Highsmith in place of Love.

“We’ll see who is available, see if Gabe [Vincent] is available,” Spoelstra said.

TNT reported that Vincent, the Heat’s starting point guard, will “very likely” play in Game 6 after missing Game 5 with a sprained ankle.

Even if Vincent returns, a strong case could be made for also starting Highsmith, who shot 6 for 9, including 3 for 4 on threes, in closing Game 5 with 15 points, two rebounds and two steals.

The Heat outscored the Celtics by two points during Highsmith’s 36 minutes in Game 5. Conversely, Love has had a negative plus-minus in every game in this series and stands at minus-20 in the series.

Highsmith couldn’t stop Jaylen Brown (who shot 5 for 6 against him) or Jayson Tatum (1 for 2), but he’s better equipped to defend a smaller Celtics lineup than Love.

Keep in mind that during the regular season, Tatum — when defended by Highsmith — shot 2 for 14 with three assists and four turnovers, per the NBA’s tracking data. Tatum took more shots with Highsmith as the primary defender than any other NBA player this season.

Though Love hasn’t defended Tatum a lot in this series, Tatum is shooting 4 for 5 when matched against Love over the past five games.

“Tatum has adjusted well trying to get off the ball more,” Highsmith told Bally Sports’ Jason Jackson after the game. “I just try to make it as hard for him as possible.”

During the regular season, Highsmith held the player he guarded to 42.5 percent shooting, which was best on the Heat. Those players shot better than 47 percent against everybody excluding Highsmith this season.

“You can use him on the other team’s best offensive player, whether it’s a guard or a forward,” ex-Heat coach and Bally Sports Sun analyst Ron Rothstein said.

“At 6-7, he can play little guys off the dribble. He can play bigger guys out on the perimeter contesting their shot. He’s got some game. Haywood Highsmith… has a fairly bright future. He can take you off the dribble. He can make an open three. He’s not a bad passer. He’s a really good defender. He’s long, he’s athletic. He’s a good rebounder, too.”

Highsmith had played just 81 minutes this postseason before logging 36 in Game 5.

“With the injury to Gabe, we needed some more minutes for me, some spot minutes,” Highsmith said. “Once I got in there, I was playing as hard as I can, trying to make a difference. [But] I’d rather win than me playing well.”

Love, who played off the bench in the second half and just 14 minutes overall in Game 5, indicated he understood Spoelstra’s decision to make a change.

“H came in the second half, started and played extremely well for us,” Love said. “[The Celtics] made the adjustment, Game 2, to go smaller to a faster lineup [with Derrick White replacing Robert Williams]. They decided to take Wiliams out of that lineup in Game 2. We started trying to overpower them with size. But with how we match up with that starting unit, maybe we’ll have to give a look at something else. It’s a luxury for us being able to take our egos out of it and do what’s best for the team.”

OPEN THREES GALORE

Not only are the Celtics making far more open threes during the past two games, but they’re also getting a lot more open looks.

Per the NBA’s tracking data, Boston averaged 16.3 open three-point looks in the first three games of the series, all Heat wins. The Celtics have averaged 21.5 open three-point looks the past two games, both Celtics wins.

The Celtics shot 19 for 49 (39 percent) on those open looks in the first three games, compared with 23 for 43 (53 percent) over the past two.

▪ The Celtics forced 16 turnovers and scored 27 points off those turnovers in each of the past two games. Those 54 points off turnovers were the most scored by the Celtics in any two consecutive games this season.

CELTICS REACTION

Here’s what the Celtics were saying heading into Game 6:

▪ Jaylen Brown: “The only thing that can stop us is us…. When adversity hits, you get to see what a team is made of…Once we got things together, we all looked each other in the eyes and said, ‘Hey, we’re not going out like this….. Now it’s a series. The next two games should be fun.”

Brown praised the Heat: “Spo is a great coach. They’ve got great players that have a great mentality. Those guys play at an incredible pace. The pace they play at is kind of similar to the Warriors. They sprint to their spots. They sprint off screens. They find those pockets. They relocate. You can’t blink because they’ll relocate. You’ll lose a shooter for a three, so you’ve got to be disciplined. You’ve got to chase those guys, because all night, they’re going to be running. You’ve got to bring your track shoes.”

▪ Coach Joe Mazzulla: “Sometimes you have a bad week at work. We obviously didn’t pick the best time to have a bad week, but we did, and we’re sticking together and fighting like hell to keep it alive, and the guys are really coming together.”

▪ Tatum: “In that locker room after Game 3 was the lowest you can be, and I think everybody just kind of relaxed [after that]. Being down 0-3, you understand how that [winning a series after trailing 0-3] has never been done before. It kind of gave us a sense of just like, everybody is counting us out. I think we started to play a little more free, relaxed….

“For some odd reason, even last year, we always seemed to make it a little bit tougher on ourselves. [We have an] ability to come together, figure things out, when it’s not necessarily looking good for us. We’ve got a room full of determined, tough guys.”