Broncos rookie RB Torain out for season with torn ACL

The Denver Broncos suffered a major loss in their 34-30 comeback win at Cleveland on Thursday.

Starting rookie running back Ryan Torain suffered a torn ACL in his left knee in the second quarter of the game. He will be lost for the season.

One of Torain's agents, Troy Asmus, said Friday afternoon that an MRI exam confirmed the injury. Asmus said the initial diagnosis was that Torain suffered a "clean tear" and that he should be ready for training camp in 2009.

That does nothing for Denver, which is 5-4 and leads the AFC West.

Torain was the third Denver tailback to be shut down for the season in four days. Denver lost starter Michael Pittman (neck) and backup Andre Hall (hand) for the season in a loss to the Miami Dolphins on Sunday.

Torain, a fifth-round pick from Arizona State, made his NFL debut against the Dolphins. He broke his elbow in training camp in early August and was on the verge of winning the starting job at the time of his injury.

When Torain was hurt in camp, Denver coach Mike Shanahan compared him to former Broncos great Terrell Davis, the catalyst of their Super Bowl teams.

Torain looked as advertised against Cleveland. He had 68 yards on 12 carries and he looked like the perfect fit for Denver's zone-blocking run attack. Torain appeared to be a solution for a stagnant running game that produced 14 yards against Miami. It was the second-lowest yardage total in team history.

Now, Denver is back to trying to figure out a solution in the running game. With backup Selvin Young recovering from a groin injury that has kept him out for three games, Denver used fullback Peyton Hillis as its running back in the second half Thursday night.

Hillis is best known for blocking for Darren McFadden and Felix Jones at Arkansas.

Among the tailbacks available to be signed are former Broncos Tatum Bell, Mike Bell and Vernand Morency.

Expect Denver to be a pass-heavy offense as it tries to stay in the playoff hunt.

Quarterback Jay Cutler threw for 447 yards and three touchdowns against the Browns.

Shanahan surely would like more balance, but at this point he may not have a choice.

Bill Williamson covers the AFC West for ESPN.com.