Cavs' Donovan Mitchell (calf) uncertain for Game 5 after missing ...

Donovan Mitchell (left) talks with Evan Mobley during a stoppage in play during Game 4 vs. Boston.

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CLEVELAND (AP) — Donovan Mitchell spent the biggest game of Cleveland’s season sitting helplessly on the bench in street clothes.

In a way, it was almost fitting. The Cavs have been banged up for months.

The All-Star guard sat out Game 4 on Monday night with a strained left calf and couldn’t help as the Cavaliers fought hard before losing 109-102 to the Boston Celtics, who took a 3-1 in their East semifinal series.

Mitchell, who has been dealing with a left knee injury since the All-Star break, got hurt in the closing minutes of Cleveland’s loss on Saturday in Game 3. He spent the past two days receiving round-the-clock treatment on his calf but couldn’t go.

It’s unknown if he’ll be available for Game 5 on Wednesday in Boston (7 ET, TNT) as the Cavs try to keep alive a season that injuries have defined.

Although they were missing Mitchell and starting center Jarrett Allen, who missed his seventh straight game with a rib injury, Cleveland pushed the top-seeded Celtics to the limit. The Cavs were within five in the final two minutes, but Max Strus missed a 3-pointer and Cleveland couldn’t get a defensive stop.

“They’re a connected group that has been resilient all year long,” said coach J.B. Bickerstaff. “We’ve been through a ton with this group, and never once has our group folded when guys have had opportunities or the team needs them to step up.

“They’ve always stepped up and given us a chance, and I thought they did a great job of that tonight.”

Mitchell has been everything for the Cavs in his second postseason for Cleveland. He came into Monday’s game averaging 29.6 points in these playoffs, which will lead into an interesting summer for him and the Cavs.

He’s eligible to sign a contract extension but has not indicated he’s eager to stay or leave Cleveland.

Allen hasn’t been able to play since getting hurt in Cleveland’s first-round series against the Orlando Magic. He had been dominant before getting hurt, averaging 17.0 points and 13.8 rebounds. He grabbed 20 rebounds in the Cavs’ Game 2 win over the Magic.

Mitchell did not participate in the team’s morning shootaround, opting for more treatment and film work.

He arrived at Rocket Mortgage FieldHouse shortly before 5 p.m., two hours before the opening tip and by then knowing he couldn’t play.

Darius Garland stepped up in Mitchell’s absence, scoring 30 points and adding seven assists in 40 minutes.

“He carried the load for us,” Bickerstaff said. “He put pressure on them offensively, made them make tough decisions, and then I thought he made the right play. I thought he did a great job of sparking us and carrying us with spirit.”

The Cavs attempted a team playoff-record 48 3-pointers, a formula they may have to follow again if Mitchell is out.

“The same aggressiveness, the same attitude,” Garland said when asked what it will take to win Game 5. “Try to get as many 3s up as we can, especially if they’re falling. And then just keep being aggressive going to the rim.”

Evan Mobley and Caris LeVert added 19 points apiece for the Cavs, who were upset that they only attempted seven free throws to 24 for Boston.

“I’m not going to go into it, but that’s ridiculous for the amount of drives that we have,” Garland said. “The amount of paint attacks. Just having seven free throws in a basketball game when they’re getting 24, I don’t know. I’m not one of the refs.

“I’m not one of those guys with a striped shirt, but I know how many times I get hit. I know how many times my teammates get hit, put on the floor and we can’t reciprocate it. It’s tough.”