LAKE FOREST, Ill. -- Chicago Bears defensive end Bryan Robinson fell down stairs after tripping over his dog, leaving him with two broken wrists and in need of surgery.

Robinson is scheduled to undergo surgery on his left wrist on Friday, but was not expected to require an operation on his right wrist, his agent, Mark Bartelstein, said Thursday.

The 6-foot-4, 238-pound Robinson was injured while trying to brace himself from the fall.

Robinson, who signed a $20 million, five-year contract in December, has started 53 consecutive games dating to 1998.

Bartelstein said it wasn't clear when Robinson would be ready to play, although Robinson told the Chicago Sun-Times that he would be ready for training camp.

"We'll see for sure after the surgery," he said.

The 27-year-old Robinson had 4.5 sacks, 72 tackles and 12 deflected passes last season for the Bears, who allowed a league-low 203 points.

The Bears went 13-4 last season and made the playoffs for the first time seven years. Chicago lost to Philadelphia 33-19 in the first round of the playoffs.

When Robinson, a former Fresno State star, was eligible for unrestricted free agency after the 2000 season, the Bears designated him a "transition" player to retain his rights and to limit his mobility. He originally signed the one-year "transition" offer, then last December signed a five-year, $20 million extension through the 2006 campaign.

The new contract included a $4 million signing bonus.

Claimed on waivers from the St. Louis Rams in 1998, Robinson moved into the starting lineup for the second half of that season and has been a Bears fixture ever since. He is expected, in a short time, to be able to perform most cardiovascular activities to maintain his conditioning before camp opens.

ESPN.com senior writer Len Pasquarelli contributed to this story.