Smith had an MRI on Wednesday after leaving practice with the injury he reportedly suffered during Sunday's win against the Seattle Seahawks.
He was named NFC Offensive Player of the Week after the Cowboys rushed for 162 yards against the previously top-ranked Seahawks run defense. Quarterback Tony Romo was only sacked once. He is the first offensive lineman to win the award since the Kansas City Chiefs' Brian Waters in 2004.
Smith and the offensive line have been key in the team's hot start to the season. As a team, Dallas leads the NFL with 962 rushing yards, and DeMarco Murray (785 yards) has 243 yards more than any other player. With more emphasis on the running game this season, the Cowboys lead the NFC in time of possession at just under 35 minutes per game.
Smith, who is in his fourth season, was the No. 9 pick in the 2009 draft. He was named to the Pro Bowl and All-Pro Second Team last season. He signed an eight-year extension with the Cowboys before this season.
Dallas is 5-1 and in first place in the NFC East. The Cowboys host the New York Giants on Sunday at 4:25 p.m.
- Paul Palladino