Tyronn Lue's absence is starting to cause concern.

The Cavaliers survived Saturday's 114-109 win against the Bulls as their coach exited with an undisclosed illness for the third time this season, leaving associate head coach Larry Drew to take over.

"I'm not sure exactly what it is," Drew said after the game, via ESPN. "I just know that before coming out in the second half, he wasn't feeling well. And I thought that there was a chance that he would (eventually) come out, but he just wasn't well enough to come out, so we had to just go on."

Lue had previously sat out a Dec. 21 win over the Bulls and a Feb. 6 loss the Magic. When asked if Lue's health has affected the team this season, LeBron James couldn't deny his impact.

"I mean, he's the captain of the ship, so absolutely," James said. "We worry about his health, obviously. That's way more important than this game of basketball. We know he's been doing everything he needs to do to stay healthy. Take even more measures to get himself right. Everything that's been going on with our year, it's just another one.

"It doesn't catch us off-guard because he's been dealing with it for so long now. But any time he doesn't come back to the bench, it's just an alarm going off, obviously. Like I said, his health is more important. He's not going to talk about it, so I don't want to talk about it no more either. That's just how he is, and I don't want to get too much into it."

The Cavs have struggled mightily with injuries recently, as the they played Saturday without Kevin Love (hand), Tristan Thompson (ankle), Rodney Hood (back) and Kyle Korver (family medical emergency).

Despite the team's setbacks, Lue, 40, remains optimistic about his squad's outlook with the playoffs set to begin next month.