INDEPENDENCE, Ohio -- Tyronn Lue is stepping down as head coach of the Cavaliers "for the time being" to deal with his ongoing illness, which has knocked him from three games and plagued him for virtually the entire season.

Chief assistant Larry Drew will take over for Lue, beginning with tonight's game against the Milwaukee Bucks.

Lue, 40, in a statement released Monday morning by the Cavs, made clear that he intends to return this season. He said he has "had chest pains and other troubling symptoms, compounded by a loss of sleep, throughout the year."

"After many conversations with our doctors and Koby (Altman) and much thought given to what is best for the team and my health, I need to step back from coaching for the time being and focus on trying to establish a stronger and healthier foundation from which to coach for the rest of the season," Lue said in the statement.

Lue has been examined repeatedly by Cleveland Clinic doctors for months and undergone a battery of tests, and there is no diagnosis. He did not return for the second half of Saturday's win over the Bulls; previously he missed the second half of a loss to Orlando on Feb. 6 and the entire game against the Bulls on Dec. 21.

"I think it's probably well overdue," LeBron James said of Lue's stepping down. On Saturday, James said Lue's illness was impacting the team.

Team sources said the organization and Lue were in "agreement" that he had to step away now, though it was Altman who initiated the discussion with Lue. James said he didn't find out that Lue was leaving until just before shootaround.

"I'm new to it like y'all," he said.

Players (like James) and people close to Lue have been aware of Lue's condition for months. He resisted stepping away from the Cavs at various points during the season, dating to as early as November and December when the team won 18 of 19, and again in January when the team was struggling mightily.

"While I have tried to work through it, the last thing I want is for it to affect the team," Lue said. "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.

"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're all working towards."

In the same statement released by the Cavs, Altman said "we know how difficult these circumstances are for (Lue) and we support him totally in this focused approach to addressing his health issues."

Lue took over as coach in January 2016 when the team fired David Blatt. He steered the Cavs to the organization's lone championship that season -- which included overcoming a 3-1 deficit to the Warriors in the Finals -- and has a regular-season record of 118-74.

There has been no shortage of drama (and winning) for this organization over the past four seasons, but this year takes the cake. From the trade of franchise pillar Kyrie Irving, to the aforementioned winning streak and implosion, to the trading of six players on Feb. 8, to Kevin Love's panic attacks, to Lue's departure, the Cavs have endured a dizzying season in which they'll make the playoffs, but a fourth consecutive trip to the Finals seems in question.

Cleveland enters play tonight a half game ahead of Washington and Indiana for third place in the East.

At present, six players are either out or questionable to play due to injury or other circumstances: Love and Kyle Korver might play against the Bucks, while Rodney Hood, Cedi Osman, Tristan Thompson and Larry Nance Jr. remain out.

Drew, who will speak to the media tonight before the game, was a head coach for four seasons (including one with Milwaukee in 2013-14) and has a record of 143-169.

"It's obviously like losing one of your best players," James said. "Obviously the guy that's pretty much the captain of the ship, that's run the thing for the last three years. Everyone has to step up. We have coaches in place that's ready for that challenge and we have to do our job as players as well. Like I said, his health is most important and we look forward to when he comes back."

Lue is in the second season of a five-year, $35 million contract.