This report comes from CBS4 Broncos Insider Reggie Rivers.

UPDATE:  Mike Shanahan has announced that Torain will be out 6 to 8 weeks with a broken bone in his elbow.

Broncos rookie running back Ryan Torain was carted off the field during the team's 9-on-7 run-blocking period at practice Wednesday morning.

He was knocked off balance while carrying the ball and put his left hand on the ground to regain his balance.

He immediately collapsed on the turf grasping his left shoulder. Broncos head trainer Steve Antonopolus helped Torain walk to the sideline and tended to him for about 10 minutes before calling a cart to ferry the tailback off the field.

Torain, a 5th-round draft pick out of Arizona State, has been one of the stars of training camp. This injury likely means that he will miss the preseason opener in Houston on Saturday.

This is unfortunate for Ryan Torain, he had a lot of promise and from what I have heard he was doing great in camp. As I said in a comment below, this does now open the door for Anthony Alridge to show what he is made of.