NASHVILLE, Tenn. -- Confirming news that came out Wednesday, Tennessee Titans coach Ken Whisenhunt said the team will start rookie Zach Mettenberger at quarterback Sunday against Houston and going forward.

"No matter who that guy is at the quarterback position, it's his team," Mettenberger said. "I've got to step in and take control. I've done that this week, being vocal, making sure we're in the right calls, being on the same page. Absolutely, this is my team now."

"I've got to step in and take control. I've done that this week, being vocal, making sure we're in the right calls, being on the same page. Absolutely, this is my team now."

The 2-5 Titans have been anemic on offense with Jake Locker and Charlie Whitehurst under center, and they rank as the NFL's worst third-down team.

Whisenhunt said he and his staff reached the decision on a quarterback change Tuesday around midday and notified all three quarterbacks. They were still waiting at that point to see if Locker's injured thumb would allow him to be the backup, and it has.

"I think over the last couple weeks, [Mettenberger] has gotten the opportunity to get reps in practice to go with guys that are playing," Whisenhunt said. "There is no question he is a talented young player. And maybe it'll give us a spark. Offensively, we haven't exactly been lighting it up. So that's part of it in consideration."

Locker, the eighth pick overall in the 2011 draft, is now the No. 2.

But if Mettenberger plays well enough and stays healthy, the Titans may never turn back to the high draft pick, who is not under contract beyond this season.

"It's not easy, it's frustrating, it's disappointing," Locker said. "There are still nine games left in the season. I will be Zach's backup, and there is a responsibility with that that I don't take lightly. Be prepared for the game and try to help Zach, in any way I can, have success."

Whitehurst has been dropped to No. 3. The Titans haven't dressed three quarterbacks for a game this season.

Mettenberger said he feels ready.

"I've been preparing and anticipating this happening really since the day I was drafted," he said.

Mettenberger shaved a beard he's had for some time before meeting with the press. He left a mustache and soul patch that position him for his Halloween costume, Ben Stiller's outfit in the movie "DodgeBall."

"Can't you tell?" he joked.