Dan Koppen carted off in Miami

A thin Patriots offensive line got thinner with Dan Koppen's injury Monday night. (Greg M. Cooper/US Presswire) The Patriots already had depth issues on the

A thin Patriots offensive line got thinner with Dan Koppen's injury Monday night. (Greg M. Cooper/US Presswire)

The Patriots already had depth issues on the offensive line heading into Monday night's season opener at Miami. Those problems got a lot worse late in the second quarter, when starting center Dan Koppen was carted off with a left ankle injury. It was announced Tuesday that the injury is a broken ankle, and that there's no timetable for the center's return.

Initially, Koppen was deemed questionable to get back into the Dolphins game, before word coming out of the half announced that Koppen wouldn't be coming back. Koppen was blocking on a third-and-1 sneak by Tom Brady when Miami's Karlos Dansby rolled onto his left leg. Koppen started writhing in pain on the ground as multiple New England players waved for the team trainers.

The Patriots entered Monday without starting right tackle Sebastian Vollmer, who's been dealing with a back injury. His absence forced rookie Nate Solder from his left tackle spot to the right side.

Dan Connolly jumped in at center with Koppen out -- Connolly had been rotating with new acquisition Brian Waters early in the game.