Klatt, a junior, practiced for the first time Tuesday after suffering the neck injury. He said health-wise, he will be ready to play if called upon vs. Iowa State.
Though Barnett declined to elaborate on the details of what went into the decision, which he announced to media after Tuesday's practice, Barnett said, "We're going to start James Cox at quarterback this weekend. My perception at this point in time is that's the best thing for our football team. There's a lot of things that go into it. Klatt's injury figures in, but that wasn't the reason for the decision."
Asked if it was a permanent move, or a one-game experiment, Barnett declined to comment. Klatt seemed to indicate that it was permanent, but said that "anything can happen."
"He's the starting quarterback right now," Klatt said. "I'll be the backup. Hopefully, James plays real well and gives this team a chance to win the football game. If he goes down, I'll be ready."
The Colorado offense looked sharp in the first half in the season-opener vs. Colorado State, and in the entire win over North Texas. Other than that, however, the Buffs have struggled to make plays when they've had the ball.
Cox was 15-of-21 for 175 yards with one touchdown and two interceptions in the second half vs. OSU. It was the first meaningful game-action in his career at CU. One thing that was obvious Saturday was the added mobility Cox brings to the field, in comparison to Klatt.
"I thought James came in and showed a lot Saturday," Barnett said. "All fall camp he's shown the ability to make plays with his feet. Our team will go right on."
The move is bold because Klatt has been a strong team leader ever since he won the starting quarterback job prior to last season. He quickly won the hearts of CU fans and the trust and respect of teammates and coaches with his stellar performance in last season's win over CSU at Mile High Stadium. He threw for 402 yards in the come-from-behind victory.
Asked what prompted the move, offensive coordinator Shawn Watson said, "It's just basically what was best at this time for Joel, and what was best for our football team."
Watson declined to elaborate on what he meant by what was best for Klatt. But Barnett had said in recent weeks that Klatt had shown a tendency to try and do too much when he was on the field this season.
Barnett and Watson met with Klatt Tuesday morning to give him the news. On Tuesday, Klatt showed his maturity and said he would work hard to help prepare Cox for the starting quarterback duty.
"He deserves a chance at this," Klatt said. "I'm just going to try to do whatever I can, in whatever role I can, to help this ball club."
Cox was told of his new role around 1:30 p.m. Tuesday, just before practice. He didn't seem overwhelmed with the situation after practice.
"The only thing that was different about practice today was that I got all the reps with the ones," he said. "It felt good."
Cox also gave a nod to Klatt.
"I don't know if I'd be able to do it without him," he said. "He's going to do nothing but help me."
Cox actually played in mop-up duty last year vs. Iowa State.
This will mark the sixth-straight season CU has changed starting quarterbacks during a season. However, this is the first time since 2000 that the change hasn't come because of injury.
Billingsley and Hollis done for the season
Junior safety J.J. Billingsley had exploratory surgery on his knee Tuesday. Barnett said Tuesday evening that he would be on crutches for four or five weeks, and would not play again this season.
"We'll rehab it and get him ready for spring football," Barnett said."
Billingsley has seen action in two games this season and will seek a medical redshirt.
Junior linebacker Chris Hollis had his neck examined by a specialist in Philadelphia Monday, and it was determined that his injury, which occurred in practice two weeks ago, was not career-ending. However, Hollis will not play again this season and will seek a medical redshirt.