CLEVELAND (AP) — The on-court issues have been obvious for weeks. The Cavaliers’ problems now extend to their locker room.

The champions are showing cracks — and weakness.

Instead of celebrating a 135-130 double-overtime win over an Indiana team fighting for a playoff spot on Sunday, the Cavs were in damage control.

LeBron James apologized to Tristan Thompson, who was still fuming after a screaming match during a timeout with his world-famous teammate. Kyrie Irving and J.R. Smith both made quick exits before speaking with reporters, and coach Tyronn Lue did everything he could to re-direct pointed fingers at him.

“My fault,” Lue said. “Blame it on me.”

Unless the Cavs get it together in the next few weeks, Lue may have to accept greater culpability. Cleveland’s postseason run could be shorter than anyone expected.

As James iced his ankles and knees after battling Paul George for 52 draining minutes before putting away the Pacers, Thompson was having trouble cooling off. The hard-working power forward briefly spoke with a team media relations member and general manager David Griffin before addressing a small group of reporters while James was speaking to the larger media group surrounding him in his corner locker.

Thompson’s answers were curt, programmed.

“We’re family,” he said. “Move forward.”

Thompson was more animated during the second OT, when he and James screamed at each other after some defensive breakdowns allowed George to get free for a pair of 3-pointers. While Cleveland’s crowd stood and roared during a timeout, Thompson and James squared off and yelled at each other, awkwardly forcing Lue and their teammates to play peacemakers.

Truth be told, the Cavs’ defense has been a major issue all season. They struggle to stop simple pick and rolls; they lack a rim-protecting big man (a role Andrew Bogut was going to fill before breaking his leg); they have been disjointed for months because of injuries; and they’ve lacked focus at both ends of the floor, relying on 3-pointers to overcome defensive deficiencies.

James, who was guarding George, seemed to expect that Thompson was going to switch on screens. He didn’t and George made the Cavs pay, scoring 19 consecutive points during one stretch of the overtime sessions.

The three-time champion expressed remorse from showing up Thompson, saying he could have handled the situation with his younger better. There have been many times when James is speaking with reporters when Thompson will yell goodbye before leaving the locker room. There was none of that love Sunday, with the postgame vibe subdued and strange.

Just last week, James insisted the team’s recent slide — a 7-10 record in March — had not affected camaraderie.

Well, there may be some exposed nerves now.

Another glaring deficiency in Sunday’s win was the Cavs’ inability to execute inbounds plays in crucial situations. Twice, Kevin Love attempted to pass to James and both times George was able to get deflections.

James blamed the poor execution on a lack of practice. The Cavs played 12 road games in March, making it difficult for Lue to schedule workouts while making rest for his players a priority.

“We haven’t practiced anything, especially late-game situations,” James said. “I can’t remember the last time we had a late-game situation.”

There’s certain to be some big ones ahead, maybe as early as Wednesday, when the Cavs visit the Boston Celtics, who have overtaken Cleveland and currently lead the Eastern Conference.

James, who is trying to reach the NBA Finals for the seventh straight time, has seen it all during nearly 14 pro seasons. He’s had disagreements with teammates before, which is why he did all he could to diffuse tension afterward.

“I apologized,” he said. “It’s cool.”

James knows this isn’t the time for a family feud. The Cavs need to be united before setting off what promises to be a much tougher road through the East, where teams like the Celtics, Washington Wizards and even the Chicago Bulls, who went 4-0 against the Cavs this season, don’t fear James and Co.

That’s for the future. Right now, with six games left in the regular season, the Cavs need to worry about themselves.