Garrett says Costa's back went out on the first play against Giants, 'wasn't quite right'

Jason Garrett said center Phil Costa wasn’t quite healthy enough when the game started Wednesday night, and his back had a problem on the first play.

“He was determined to play, and his back really wasn’t quite right,” Garrett said Thursday at Valley Ranch. “We really found out about it on the first play. He tried to gut it out on Plays 2 and 3, but then we had to put Ryan in on the second series.”

Garrett said Costa will undergo and MRI.

Costa missed the last two weeks of training camp because of back tightness. He got in the final preseason game, playing 12 plays.

“I thought he did a really good job working to get back, and it just shows you the kind of mental toughness that he has,” Garrett said.

Garrett declined to talk about potential competition from Costa from Ryan Cook, the seventh-year veteran acquired in a trade with the Miami Dolphins last week. Cook took over for Costa against the Giants.

“I don’t want to get into that right now,” Garrett said. “We want Costa to get back. Costa’s been our starting center for a reason. We like him a lot. But at the same time, we want to make sure he’s healthy.”

-- Carlos Mendez

Twitter @calexmendez