Okur needs surgery and will likely miss the world championships this summer in his native Turkey. He flew home to Salt Lake City on Sunday after an MRI revealed the tear.
"It's horrible, man. We feel bad for Memo," Jazz forward Carlos Boozer said.
Okur was injured while driving to the basket in the first half of Utah's Game 1 loss at Denver on Saturday night. Before the game, he had taken a painkilling shot to treat his Achilles tendinitis, which he had been dealing with since April 7.
O'Connor said he doesn't believe the injection had anything to do with Okur tearing the tendon.Okur's right leg slipped as he was driving, shifting all his weight to his left leg, which twisted awkwardly as he fell to the floor -- what O'Connor called "a perfect storm."
"We would never have put a player in a compromising position if there was any indication that the shot would have masked anything or done anything like that," O'Connor said. "We would have never done that. We'd never put a game ahead of a player's health. ... That's not in our DNA."
O'Connor said Okur's injection "was certainly his call."
"Is it related? I'm sure in some way, shape or form, everyone's going to put it on the fact that it is, but [team doctors] didn't feel there was any additional risk in doing that," O'Connor said.
Following surgery, Okur will need three months before he can begin rehab, which can take several more months, likely preventing him from playing in the world basketball championships Aug. 28-Sept. 12.
"It's a sad injury, bad injury, I wish him the best," Jazz point guard Deron Williams said as he sat dejectedly on near practice court at the Pepsi Center. "Memo's a big part of our team. He stretches the defense. He's a guy you really can't replace just because his inside-outside game is really unmatched."
Okur's absence saps the Jazz of another playmaker who spreads the court.
"He's definitely a threat out in the perimeter," Nuggets acting coach Adrian Dantley said. "With him not playing, it helps our schemes a little bit defensively. He's a very important part of their team, an important part of their offense."
Jazz coach Jerry Sloan was his usually stoic self when discussing Okur's season-ending injury.
"That's just part of basketball. Not anything you can do about it. We still have to play. We just wish him the best trying to recover," he said.
O'Connor said the Jazz have made some recommendations but it will be up to Okur to pick his surgeon.
Information from The Associated Press contributed to this story.