Washington Redskins safety Brandon Meriweather’s MRI exam Sunday of his injured left knee revealed no significant damage, according to a person with knowledge of the test result.

It’s not clear how long Meriweather will be sidelined but it appears that the Redskins avoided suffering a loss to their defense, just as they did with linebacker Brian Orakpo’s injury. According to Orakpo’s agent, Ben Dogra, the MRI taken Sunday of the injury to the area of Orakpo’s left shoulder showed no serious injury and Orakpo is expected to play in the regular season opener.

 Meriweather hurt his left knee in the first half of Saturday night’s preseason loss at Chicago. He was injured on a touchdown run by Bears tailback Michael Bush.

The Redskins signed Meriweather as a free agent in the offseason and he has been one of the team’s two starters at safety in training-camp practices and through two preseason games