Vikings QB Jackson has sprained knee ligament

The initial diagnosis was that Minnesota Vikings quarterback Tarvaris Jackson suffered a bruised right knee in Saturday's preseason game at Baltimore, but further tests revealed a sprain to his medial collateral ligament, according to a person with knowledge of the situation.

Vikings coach Brad Childress was not available for comment Sunday, but it's reasonable to think the injury could keep Jackson out of the most important game of the preseason Saturday against the Pittsburgh Steelers.

Teams typically treat their third preseason game as a dress rehearsal for the regular season, giving starters extended playing time. Jackson's status for the preseason finale at Dallas on Aug. 28 also is unknown, but it's hard to imagine he would not be ready to play in the season opener Sept. 8 at Green Bay.

Jackson suffered the injury while scrambling in the first quarter of a 23-15 victory against the Ravens. Rather than slide to avoid contact, Jackson took on a hit by Ravens linebacker Ray Lewis, then safety Dawan Landry.

The Vikings had Sunday off. The team is expected to give an update on Jackson today.

Veteran Gus Frerotte replaced Jackson and went 4-for-9 for 69 yards and a touchdown.

• RAMS -- St. Louis offensive guard Mark Setterstrom fractured his left kneecap in the second half of Saturday's preseason game against San Diego, and he will be placed on injured reserve.

Coach Scott Linehan said Setterstrom, a seventh-round pick in 2006 who has made nine starts in two seasons, would have surgery later in the week.

Quarterback Marc Bulger, who hurt his shoulder when hit from behind while preparing to throw in the second quarter, was believed to be fine. Linehan said team doctors were not concerned.

Another offensive lineman, Brandon Gorin, will also be placed on injured reserve with a shoulder injury sustained in the preseason opener at Tennessee. Gorin made eight starts at tackle and played in 11 games last year, filling in when three line starters ended the year on injured reserve.

• STEELERS -- Pro Bowl safety Troy Polamalu could return to practice Tuesday.

Pittsburgh coach Mike Tomlin indicated after weekend practices that the team is ready to remove Polamalu from the physically unable to perform list when the team breaks camp today in Latrobe, Pa., and heads back to the Pittsburgh facility.

Polamalu has been out with a sore hamstring.

• TITANS -- Rookie receiver Lavelle Hawkins is wearing a walking boot on his left ankle, and coach Jeff Fisher said an MRI exam showed a sprain that likely will keep him out of Tennessee's third exhibition at Atlanta.

But the rookie said he's a fast healer and hopes to return quickly enough to play Friday night. Hawkins caught two passes for a team-high 70 yards in the Titans' 17-16 win over Oakland, including a 51-yard touchdown for his first in the NFL.

Cornerback Nick Harper missed Sunday's practice and has not worked out since suffering a concussion in the Titans' preseason opener. Fisher said he expected that Harper would practice today.

Linebacker Keith Bulluck sat out with an injured right calf, and Fisher said it was too early to know if Bulluck will play against Atlanta.

• BILLS -- Buffalo tight end Derek Schouman missed practice and is out indefinitely with a strained left knee, all but ending his chance to win the starting job out of training camp.

Coach Dick Jauron said trainers informed him that it will be two weeks before Schouman is expected to be cleared for practice, meaning the player likely will miss the Bills' final two preseason games.

• OBIT -- James Busch Orthwein, the former New England Patriots owner who played a key role in the Rams move to St. Louis, has died. He was 84.

The St. Louis Post-Dispatch said Orthwein died Friday at his home in Huntleigh, Mo., after a long battle with cancer.

Orthwein bought the Patriots in 1992 and sold them to Robert Kraft two years later.