By Tony Moss, NFL Editor -- (Sports Network) - The Minnesota Vikings could be minus the services of starting quarterback Tarvaris Jackson on Saturday, when the team plays host to the Pittsburgh Steelers in the third preseason warm-up for each club.

Jackson suffered a sprained right MCL in last week's 23-15 win over the Baltimore Ravens, and the nature of that injury suggests the Vikings would be loath to put him in harm's way for a relatively meaningless preseason game.

That said, Jackson did go through individual drills in practice this week, and neither Minnesota head coach Brad Childress nor offensive coordinator Darrell Bevell would rule the quarterback out for Saturday.

Jackson has had a solid preseason to date, completing 15-of-22 passes for 200 yards and two touchdowns without an interception or sack absorbed. His 127.1 passer rating ranks among preseason NFL leaders.

If the third-year-pro can't go against the Steelers, veteran Gus Frerotte would likely get the start with rookie John David Booty and perhaps Brooks Bollinger succeeding him in the lineup.

Elsewhere on the injury front for Minnesota, wide receiver Bernard Berrian (turf toe) is considered questionable against Pittsburgh, while ends Brian Robison (leg) and Ray Edwards (back) and safety Madieu Williams (neck) remain out.

The Steelers, meanwhile, will be looking for more positive signs from a first- team offense that has run with general efficiency so far in the preseason.

Quarterback Ben Roethlisberger is 11-of-13 for 180 yards and two touchdowns during the warm-up period to date, though he did throw an early interception in last week's 24-21 loss at Buffalo. The big play of the night for the Pro Bowl quarterback was a 40-yard touchdown pass to wideout Santonio Holmes in the second quarter.

Roethlisberger carries a 126.3 preseason passer rating into Saturday's matchup.

Safety Troy Polamalu (hamstring) and cornerback Deshea Townsend (groin) are both considered questionable for the Minnesota game.

Returning to Minnesota on Saturday night will be running back/return specialist Mewelde Moore, a member of the Vikings from 2004 through 2007. Moore is attempting to make the Steelers roster as a reserve running back and return man.

The Vikings hold a 9-2 advantage in their all-time preseason series with the Steelers, including a 17-10 road victory over Pittsburgh prior to the 2006 campaign.

The Steelers were 16-6 winners in the most memorable all-time matchup between the franchises, namely Super Bowl IX from New Orleans.