Englewood, Colo. • Peyton Manning is discovering that one of the biggest benefits to joining the Denver Broncos is their star-studded secondary.

It's helping him gauge his progress in his comeback, sharpen his timing with new targets and scrape away the rust after his lost 2011 season.

The Broncos restocked their defensive backfield over the winter after seeing Pittsburgh's four-wide receiver sets and New England's big tight ends torch them in the playoffs.

They added veterans Tracy Porter, Drayton Florence and Mike Adams, along with rookie Omar Bolden, released Andre' Goodman and wished Brian Dawkins well in his retirement.

Around the league

Cowboys • DeMarco Murray isn't ready to think of himself in the same company as Tony Dorsett and Emmitt Smith, though he is already listed among Dallas' two Hall of Fame running backs in the team record book.

On the first carry of his first start, Murray ran 91 yards for a touchdown . The only longer scoring run in Cowboys history is Dorsett's 99-yarder in 1983.

Murray ran for a team-record 253 yards in that first start, and had 601 yards in his first four — more than NFL career rushing leader Smith had over a similar stretch.

• Dallas running back Felix Jones and two other players have been cleared to practice starting Friday after passing their second-chance conditioning tests.

Jones, receiver Andre Holmes and safety Brodney Pool failed the initial conditioning test Sunday.

Chargers • San Diego running back Ryan Mathews suffered minor injuries in a car crash and is listed as "day to day."

The California Highway Patrol says Mathews lost control of his BMW while entering Interstate 8 Monday and hit another car.

Redskins • The good news for Washington is that right tackle Jammal Brown doesn't need surgery on his chronically ailing left hip. The bad news is that there's no timetable for him to return to action.

Brown, 31, missed four games last season with hip and groin injuries after being sidelined for all of 2009. —

Hall of Fame inductee Dawson was Steelers' center of attention

When Dermontti Dawson looks around at his fellow inductees for the Hall of Fame's class of 2012, he can't help but smile.

On Saturday, the six newest members of the pro football shrine will include four linemen. To Dawson, that's nirvana.

"It is kind of neat and very special to have four linemen, two defensive and two offensive, go into the hall the same year, and for them to have played in the same era," Dawson said. "Chris [Doleman] and Cortez [Kennedy], I went up against them. And Willie [Roaf] on the same side of the ball as me.

"I am surprised we had four going in this year."

It's the third time so many offensive linemen have entered the hall together. Dawson will be the 12th center enshrined, but the first since Dwight Stephenson in 1998.