The beginning of the end of Rajon Rondo’s Boston Celtics career took place on Jan. 25, 2013, in Atlanta. The veteran point guard toughed out a knee injury that turned out to be a torn ACL. The injury took place during the game, yet Rondo continued to play. He finished with 16 points, 10 rebounds, and 11 assists for his second straight triple-double.

Rondo didn’t know the extent of the injury until two days later. After a day of practice and going through his pregame routine against the Miami Heat, a team doctor suggested he take a trip to the hospital for further evaluation. While listening to the radio in the car, Rondo officially found out his injury was an ACL tear.

Rajon Rondo played through an ACL tear without knowing it

Rajon Rondo thought he hyperextended his knee against the Hawks in 2013. He was focused on Larry Bird’s team record of three straight triple-doubles and was playing on adrenaline.

“My adrenaline is going so crazy that I don’t even feel it at the time,” Rondo recently said to J.J. Redick on The Old Man & the Three podcast. “I just thought it was maybe a little bit of a hyperextension.”

Rondo said had no idea it might be a season-ending ACL injury until two days later after warming up for a game against the Miami Heat.

“We have Miami the next day, I think on ABC, and those are the games where I play really well,” Rondo told Redick. “I’m excited. It’s Miami. I got a chance to (tie) Bird’s record, blah, blah, blah.

“(Sunday) We go to the arena. I got like seven heat packs on me. I do my pregame, get out of the shower and one of the docs is like, ‘Come sit on the table.’ He does, you know, the little ACL check. He’s like, ‘You’re not playing today. Go to the hospital.’”

Rondo never played again that season.

Rondo didn’t know it was officially an ACL tear until he heard it on the radio

Rondo went to the hospital and got an MRI on the knee.

“On my way back from the MRI, the doctor that I went with turns on the radio, and it’s like, ‘Rondo’s out with an ACL tear,'” Rondo told Redick. “I’m like, ‘How in the f*** did somebody get that information before I even know that it’s an actual ACL?’

“So, I look at the doctor I’m riding with and I’m like, ‘Is this true? How are they reporting ACL when there was literally no one at the hospital?’ I figure the doctor that’s sitting next to me must’ve said something.”

Rondo admitted he was frustrated after the diagnosis.

“I get back into the arena before the game starts and Doc (Rivers) is like, ‘You’re done.’ He shuts me down. I’m emotional. I’m frustrated. Things are starting to roll for me individually and our team as well.

“That kind of messed me up and put me on an emotional rollercoaster. After that, I got about four or five opinions.”

Rondo was shut down the rest of the year and played just 30 games the following season. The Celtics traded him to the Dallas Mavericks after he played 22 games in the 2014-15 season.