After cruising to a 2-0 Eastern Conference finals lead over Boston, the Cleveland Cavaliers were humbled at home in a Game 3 loss, and needed a 42-point night from Kyrie Irving to battle back from a 16-point hole and win Game 4 on Tuesday night.

The challenge from the Celtics has sharpened the focus of the defending champs. Cleveland is expecting another unflinching effort in Game 5 from a Celtics team that isn’t backing down despite facing a 3-1 deficit in the series.

“The closeout game is always the hardest and Boston is going to make it even harder,” said LeBron James, who rebounded from a playoff-low 11 points in Game 3 to score 34 in Game 4.

While Irving’s scoring ignited the Cavs’ comeback, it was made possible by Cleveland’s defensive effort over the final 24 minutes. Cleveland limited the Celtics to 41 percent from the field and 29 percent from beyond the arc.

“We have to go in with a bunker mentality that we had in Game 1 and Game 2, to go out and do what we do, but we have to defend,” James said. “We have to execute offensively. We have to have low turnovers, and we have to try to make them miss because some of those guys play a lot better at home. That’s just how the game be played.”

WHILE Heading home to the Garden should be a comfort, the Celtics haven’t always played that way this postseason.

But with elimination one game away following the 112-99 loss Tuesday night, home is all they have left. Game 5 will find them trying to improve on a rather middling 5-4 playoff record at the Garden.

“We’re humble enough to know we haven’t played well at home, and we want to give our home crowd a better outing than we did the past two games,” Jae Crowder said. “We’re right there where we want to be – we’re locked in.”

Crowder wants to hear from the Garden crowd.

“I’m expecting our fans to be able to carry us a little bit and be behind us,” he said, “and personally I feel like it’d be a great time for us to get a win, especially on our homecourt.”

Said Al Horford: “A lot of energy. We need it to be very lively and we’ll go out there and we’ll fight. I’m just excited that we have another opportunity and hopefully be able to come out on top.”

Crowder strained his groin after falling and sliding into a split in the third quarter, though he was able to return. Of course, that meant chasing LeBron James around the floor on defense in a diminished capacity.

The Celtics are operating on a more limited pre-draft workout schedule right now. Director of player personnel Austin Ainge said workouts of candidates for the No. 1 pick in the June 22 draft will occur after the team’s season ends.

Stevens, after all, has to be on hand when the likes of Markelle Fultz and Josh Jackson do their individual workouts for the team. LaVar Ball, the outspoken father of Lonzo Ball, has said his son will only work out for the Los Angeles Lakers. Ainge noted the Celtics have not heard that directly from the Ball camp.

“He has publicly said (Lonzo) won’t work out, and that’s what we have to go by,” Ainge said.

President of basketball operations Danny Ainge and his staff will travel for some workouts, possibly including Fultz. But there will predictably be only a limited amount the team can learn from the sessions. None of the players in this group will work out against another player.

“They’re all one-on-none,” Austin Ainge said. “The only one last year who did work against other players was Jaylen Brown, the No. 3 pick, and that’s because he didn’t have an agent.”

Thus far the Celtics have worked out second-round prospects and early-entry players who might still withdraw their names from the draft.

According to Danny Ainge, Isaiah Thomas is prepared to take his time in pursuit of the right solution for his injury.

“We’re not in a rush,” said Ainge, who added that so far Thomas’ meetings have been with team physician Brian McKeon and his medical group. “There won’t be any procedures until everything calms down in the hip joint. He’s clearly not going to play. If we win three straight games and stay alive, you’re not going to see Isaiah Thomas coming back.”

Ainge said he anticipates Thomas rejoining the team Thursday night for Game 5.

“It’s been very tough for him, being away from the team,” Ainge said.