CLEVELAND -- Already heavy underdogs in this Eastern Conference semifinal series against the Boston Celtics, and trailing 2-1 in this best-of-seven affair, the Cleveland Cavaliers were dealt a massive blow after star guard Donovan Mitchell was officially ruled out for Monday's Game 4 with a calf strain.

But instead of a routine Boston blowout, this one was anything but, as the Cavaliers gamely hung in there for the vast majority of the 48 minutes before eventually falling 109-102 in front of a sellout crowd here at Rocket Mortgage FieldHouse.

"To be expected, right?" said Jayson Tatum, who led the Celtics Monday with 33 points, 11 rebounds and 5 assists in just under 44 minutes. "When the best player goes out, everybody has more freedom, more opportunity.

"Obviously, we knew it wasn't going to be easy. It's the playoffs, they don't want to go home. Give them credit ... they played hard from beginning to end and made big plays on both ends. They hit big shots, so it was a battle, and it was fun out there."

Mitchell hurt his calf late in the fourth quarter of Game 3, at the end of a stint that saw him play over 22 consecutive minutes in the second half. After not being present at all during the team's shootaround Monday morning at its practice facility, he was officially ruled out roughly an hour before tip Monday evening.

That Mitchell's absence came after yet another brilliant performance, in which he scored 33 points to go over 25 for a sixth straight game in these playoffs, only added to the disappointment.

But then Cleveland -- with LeBron James sitting courtside across from Boston's bench alongside his wife, Savannah, and agent, Rich Paul -- got out to an early 8-2 lead over the opening two minutes of the game behind a couple of quick triples from Max Strus, part of Cleveland's 6-for-7 start from behind the arc.

It was a start that made clear the Cavaliers weren't going to go down without a fight, even without their star guard available to help.

"I mean, they laid it all out there," Cavaliers coach J.B. Bickerstaff said. "They gave us everything that they had. They competed at a high level. They played the game properly. I'm proud of the guys, the way they went out and scrapped and competed and gave ourselves a chance."

It was a chance, though, that ultimately proved to be fleeting, as that hot shooting start gave way to the Cavaliers shooting 9-for-41 from behind the arc over the remainder of the game. In the three losses in this series for Cleveland, Mitchell has gone 11-for-23 from 3-point range.

His teammates? A combined 27-for-103 (26.2%), including a total of 15-for-48 from 3-point range in Game 4.

"The same aggressiveness, the same attitude, try to get as many 3s up as we can and then just keep being aggressive going to the rim," said Darius Garland, who had 30 points and 7 assists for Cleveland, when asked what the plan of attack will be in Game 5 whether or not Mitchell is available.

"When we're going to the rim, they're sending about three bodies so the open kick-out is there. So that's how we're getting so many quality looks at the 3-point line. And just try to buckle down defensively, try to hold Jayson and Jaylen [Brown] to some tough 2s and try to run Derrick White, Payton Pritchard off the line and just keep being us, man.

"We just have to fight through all of this. It's not going our way, but just keep fighting. That's what we always do."

The Celtics will head into Game 5 looking to close out a team at home for a second straight series after doing so in five games against Miami in the first round. They will also have a chance to overcome what has been a seasons-long issue in terms of their playoff performances at home.

Over the past three postseasons, Boston is 14-14 at home -- the most games played (28) without a winning record at home over three postseasons in NBA history, per ESPN's Stats & Information research. On the other hand, the Celtics are now 18-7 on the road over that span.

"There's nothing better than winning a playoff game on the road," Brown said. "It's like everybody against you guys, you come here with the guys in the locker room. It's a tough environment, the crowd was great, but as a competitor, it's really fun to be in an environment like that, win on the road.

"Now it's time to go back and play well in front of our fans and give them something to cheer for and try to get a win."