Jeff Fisher said Monday that an MRI exam showed the extent of Collins' injury, which occurred at the end of the first half of a 29-17 loss at Miami.
"I don't know how many. He certainly won't play this week or be available to play the next two," Fisher said.
Fisher said Collins' injury didn't necessarily mean the Titans will make a move to add an experienced quarterback, even though rookie Rusty Smith, a sixth-round draft pick from Florida Atlantic, will be backing up Young. Fisher said Young was fine and didn't have any issues with the sprained left ankle that had kept him from starting himself against Miami.
"I think we can assume that the ankle issue is behind him," Fisher said of Young. "We expect him to practice this week."
That means the quarterback shuffle the past three games back and forth between Collins and Young due to injuries will stop Sunday when Young returns to the lineup against the Washington Redskins. Fisher still had to deal with lots of questions Monday on why Young was healthy enough to play the second half but not start.
Young had been excused from staying in Nashville during the team's bye weekend for treatment on his ankle. He went back to Austin, Texas, for the opening of the steakhouse bearing his name. Fisher defended that move, saying Young had been placed in a walking boot with nothing really to do except rest.
"If we felt the rehab was going to help him or staying behind over the weekend, then we would've asked him to stay. It wasn't an issue," Fisher said.
But Young returned needing to work out the soreness and gain strength in his ankle. Fisher said it was clear after a couple practices that Young didn't have mobility. That led to the decision to start Collins for the second time in three games, even against a franchise that the veteran had been winless against in four previous starts.
"I figured that giving him another week to heal up would be beneficial for him. Certainly didn't want to put him in the ballgame and have him reinjure the ankle because he could miss more time. Three or four weeks if he had a problem," Fisher said.
Collins, who already had a torn tendon in the middle finger on his right, passing hand, was horrible against Miami. He was 9 of 20 for 51 yards and got only one field goal out of three drives that started either in Dolphins' territory or near midfield.
Young wasn't much better once he came in. He had the Titans' second turnover, fumbling on his third play in the game. Miami turned both fumbles into touchdowns. Young did throw for a touchdown and 92 yards but was intercepted in the end zone to end Tennessee's comeback effort in the final minutes.
The quarterback drama and poor play overshadowed the debut of Tennessee's big bye week acquisition in Randy Moss. He was targeted only four times with one catch, though he did draw a pass interference flag to set up the Titans' first TD drive. Fisher said he heard no complaints whatsoever from Moss.
"He was excited to play, and I think he was a factor in the ballgame," Fisher said. "Really in tune to what they were doing, and he blocked. This might've been his best blocking day ever, but he was into it. He worked hard."
Moss' biggest effect came in the run game where Hall said they saw six and seven defenders at the line for the first time this year to defend Chris Johnson. He responded by running for 117 yards on just 17 carries.
"Just Randy being on the field is a good impact for us," fullback Ahmard Hall said.
But Moss doesn't play defense, a unit gashed for 323 yards passing by a Miami team that used three quarterbacks due to injuries. He also didn't help the Titans improve offensively on third downs. They were 5-of-16 for the game but 2-of-10 early as they went three-and-out five times.
"The more comfortable we get with Randy in the lineup, the better we will be and we'll be all right," Johnson said after the game.
Now the Titans return home where they will play four of the next five having blown a one-game lead in the AFC South with a two-game skid on the road. They now trail Indianapolis (6-3) by a game. After they host the Redskins, four straight games will be in the AFC South with a sense of urgency, according to Hall.
"We let a lot of close games get away," Hall said. "We're still in control of our destiny."
Fisher said he allowed Moss to stay in Miami to wrap up personal business.