Despite his condition, Irving vowed to play in Friday's Game 2.
"Right now, I'm pretty confident I'll go," Irving said after the game, visibly frustrated by his injuries affecting yet another one of his postseason performances.
The disappointment of Irving's health failing him was clearly weighing on the fourth-year guard as he sat in front of his locker with his head in his hands and a stoic look on his face for several minutes after the media dissipated following postgame questions.
"This is obviously one of the most frustrating things I've ever dealt with, just from [when] we do days and days [of rehabilitation] and you go out there and it's nothing like simulating a game," Irving said. "So, for me, I'm just going to continue to do what I've been doing and do whatever is necessary to put myself out there."
Irving tweaked his left knee when trying to make a play in the lane midway through the third quarter.
"The most frustrating point is seeing holes in the defense that I'm used to attacking," Irving said. "I tried to make one move and accelerated and then I stopped and I passed it to Mozzy [Timofey Mozgov]. Mozzy missed the shot, and I came right out in the third quarter."
Irving sat for the final 5:45 of the third quarter as the Cavs increased their lead from two to seven by the start of the fourth quarter.
Irving played another brief stint in the fourth quarter, checking in with 11:42 to go and then subbing back out for good with 8:39 remaining and Cleveland ahead by 11.
Atlanta cut the Cavs' lead all the way down to four with 57.2 seconds left, but Irving was not reinserted in the game as the Hawks mounted their comeback.
"In terms of me being in specific times of the game or anything like that, mainly, it's a two-part deal of myself and the coaches communicating and guys just going out there and continuing to play, especially when we have a great rhythm out there," Irving said. "I'm all about just winning, and that's the only thing that matters to me at the end of the day."
Coming into the conference finals with six days off, having not played a game since the close of the second round, Irving expressed optimism about how his body was responding to treatment.
But the same tendinitis in his left knee and right foot strain that have bothered him since the first round against Boston continued to hobble him against the Hawks.
"At this point, from the compensation on my right foot, my left knee is a little bit more stiff than I would like it to be, but like I said before in the past series and like I'm going to continue to say, it's just no excuses," said Irving, who also had an ice pack on his right knee as he spoke to reporters. "I got to continue to put myself out there and put myself in the best position for my teammates and whenever they need me I'm out there when called upon, and I'll do whatever it takes."
Irving finished with 10 points on 4-for-10 shooting, six assists and three rebounds in 27 minutes.
Defensively, he had a hard time staying in front of Atlanta's Jeff Teague.
LeBron James said it's his responsibility to try to shepherd Irving through the mental challenge that the injuries present.
"It's tough, and I know it sucks for him. This is the moment he's been waiting for. It's the biggest stage, and physically, he's not capable of doing what we all know he's capable of doing," James said. "Hopefully, it doesn't get into his mind. For me, that's my role at that point: to let him know when he's on the floor, no matter what he's going through, we need him to be as aggressive as he can be with the injury and not worry about things that he cannot control.
"Only worry about the things that he can control, and like I said, that will be my job to help him understand that no matter what he's going through physically, never let it creep into his mind, where it affects him mentally."