Manny Ramirez Broncos
Manny Ramirez is in the lead to start in place of Dan Koppen.

The favorites to win the 2013 Super Bowl received some bad news on Monday when the Denver Broncos learned that Dan Koppen had torn his ACL. The center suffered the injury during practice, and will almost certainly miss the entire upcoming season.

The injury is another blow to Denver’s offensive line. Koppen was signed when J.D. Walton underwent additional surgery on his ankle that he fractured last September.

Koppen started for the Broncos last season in Walton’s absence. He did a good job of providing protection for Peyton Manning, who was second in the NFL with a 105.8 passer rating. Providing Manning with enough time to throw might be most important factor for Denver's Super Bowl aspirations.

With training camp already underway and the preseason set to begin in less than a week, the Broncos don't have many options to find a new, reliable center. Denver will likely search for Koppen's replacement within their current roster.

Manny Ramirez will get a chance to start in Koppen’s absence. He has taken the snaps at most of the Broncos practices this offseason and started at right guard for Denver 11 times last year.

Ramirez has been in the league for five years, but has no experience at center. That hasn’t fazed head coach John Fox, who appears ready to start the season with Ramirez in the middle of the line.

"Manny Ramirez is our starting center, and has been all offseason," Fox said. "We feel decent where we are. You always hate losing guys for the season, but we march on."

C.J. Davis moves up on the depth chart with Koppen done. He received limited playing time last season, but is considered a solid option under the circumstances. Philip Blake is also on the roster at center, but the fourth-round pick in 2012 missed most of his rookie season with a hand injury.

Denver did make one move when Koppen went down. The club signed center Steve Vallos, who has been in the NFL for six years. He was a free agent after been on the Jacksonville Jaguars and Philadelphia Eagles in 2012. Vallos has nine starts in his career.

A depleted offensive line could play a major role in slowing down the Broncos offense this season. Manning was very effective last season, in large part due to the protection he received. Thirty quarterbacks were sacked more than Manning in 2012, who was taken down for a loss just 21 times in 16 games.

According to the online betting Web site Bovada, the Broncos are 6/1 favorites to win the Super Bowl. They have the same odds as the San Francisco 49ers.