Cavaliers coach Tyronn Lue is taking a leave of absence from the team to address health issues that have included chest pains and loss of sleep.
Lue said Monday in statement that tests have offered no conclusion about what the issue is and offered no timetable for his return. The coach said he feels he needs to step away "and focus on trying to establish a stronger and healthier foundation" from which to coach the rest of the season.
"While I have tried to work through it, the last thing I want is for it to affect the team. I am going to use this time to focus on a prescribed routine and medication, which has previously been difficult to start in the midst of a season," Lue said. "My goal is to come out of it a stronger and healthier version of myself so I can continue to lead this team to the championship we are all working towards."
The Cavaliers also didn't say who would lead the team in Lue's absence, though that responsibility could fall to associate head coach Larry Drew.
LeBron James said he was informed of Lue's decision Monday morning at shootaround, saying it was "probably well overdue."
"I knew he was struggling, but he was never not himself. He was just dealing with it the best way he could," James said. "Once he leaves the gym and goes home, there's things we don't know, but he was the same every single day even though he was going through what he was going through."
A stress-filled season for the Cavs has taken a toll on the 40-year-old Lue, who led them to the 2016 NBA championship after taking over for David Blatt midway through that season. They are just 40-29, third in the Eastern Conference, and have endured roster shake-ups, injuries and other distractions as they try to return to the NBA Finals.
Now they will play without their coach.
"We all want great players, we all want the best teams, but with that comes a lot of pressure as well. And what Ty Lue has had to go through this year with that team, with the trades and the injuries and the pressure, it's unrelenting," Denver coach Michael Malone said. "So I hope that he gets healthy and is able to get back in time for the playoffs and help that team win as many games as possible."
Lue spent the second half of Cleveland's victory in Chicago on Saturday in the locker room because of an illness, the second time this season he left a game because he wasn't feeling well. The former NBA guard also sat one out against Chicago at home in December.
Drew coached the second half of Saturday's game, the finale of a six-game, 11-day road trip. Cleveland is back home to host Milwaukee on Monday.
"We know how difficult these circumstances are for Coach Lue and we support him totally in this focused approach to addressing his health issues," general manager Koby Altman said.
Charlotte coach Steve Clifford also left his team to address his health this season. He took six weeks off. Medical tests revealed that the 56-year-old Clifford did not have any internal problems, but the doctor's diagnosis was the coach was suffering from severe sleep deprivation.
Just as the Cavaliers are nearing the return of All-Star forward Kevin Love from injury, they will have to go an undetermined length of time without Lue. James was asked how his absence would impact the team.
"We're going to find out," he said. "It's tough. It's like losing one of your best players, a guy that's pretty much the captain of our ship who has run the team the last three years. Everyone had to step up. We have coaches in place who are ready for that challenge. We have to do our jobs as players as well."