AP

Steelers quarterback Ben Roethlisberger said the team’s third preseason game meant nothing. In the end, it may mean something significant.

Rookie guard David DeCastro, the team’s first-round pick in the 2012 draft, has a “potentially severe” knee injury. That’s the official word coach Mike Tomlin provided after Saturday night’s win over the Bills in Buffalo. NFL Network reports that DeCastro has ACL and MCL injuries in his right knee.

An MRI is coming.

Ed Bouchette of the Pittsburgh Post-Gazzette reports that most of the players who were asked about the DeCastro injury said it doesn’t look good.

As Alper explained during the game, tackle Marcus Gilbert fell over the back of DeCastro’s right leg while DeCastro was blocking Bills defensive tackle Marcell Dareus.