PHOENIX - The Broncos have described special- teams captain Keith Burns as a coach on the field.

Now, Burns will be a coach on the field - and in the meeting room and on the sideline. Burns is set to end his 13-year playing career and join the Broncos staff as an assistant special-teams coach, Broncos coach Mike Shanahan said Tuesday.

"He's going to retire and help us out in that area," Shanahan said.

Burns becomes the second Broncos player since 2005 to move from the playing field to the meeting room. Secondary coach Jimmy Spencer, who was a player/coach with the Broncos in his last playing season (2004), has been a full-time coach since the start of the 2005 season.

Burns, who played 11 seasons with the Broncos during three stints, will assist special-teams coach Scott O'Brien. Earlier this offseason, Shanahan moved coaching assistant Ryan Slowik over to the special teams.

"I think Keith will do a great job," Shanahan said of Burns, who also played one year apiece with Chicago and Tampa Bay. "He relates with players exceptionally well, and he'll have a great mentor in Scott; he'll teach him the right way. I think Keith has a great future in coaching."

NO EXTENSION FOR WILKINSON: Shanahan said the Broncos would not extend the deadline for defensive tackle Dan Wilkinson to report to the Broncos, adding, "It's not looking real good" for the trade with Miami to go through.

The Broncos traded a sixth- round pick in April's draft to Miami earlier this month for the 34-year-old. But Wilkinson, who has been hesitant to leave his home in Maryland to attend offseason workouts in the past, has not yet reported for a physical on his ailing knee or decided if he will play in 2007.

When the Broncos could not get him to Denver for a physical by the original March 16 deadline that had been written into the trade, the teams agreed to extend the deadline until Friday.

Asked if he would extend the deadline again, Shanahan said, "No, we won't extend it."

Shanahan said Wilkinson underwent a magnetic resonance imaging exam on the knee Thursday but said Tuesday the Broncos had not seen the report.

The Broncos expect to get their sixth-round pick in next month's draft back from the Dolphins.

ROOM FOR EVERYONE: Even though the Broncos signed tight end Daniel Graham to a $30 million deal this month and took Tony Scheffler in last year's draft, Shanahan said there is room for veteran tight end Stephen Alexander on the roster and in the game plan.

Alexander, who played part of last season with a fractured rib, has one year left on his original deal with the team and is set to count $1,758,000 against the salary cap in 2007.

"I think Alexander will even be more effective because he doesn't have to play all the time," Shanahan said. "One thing, I think we felt we wore down (Alexander) last year because we played him too much. As you get older (Alexander turns 32 in November), it's tough to play all the time as a tight end; you need a break every once in a while. I think this will prolong his career."

VOTES ARE IN: The league's owners voted 30-2 (Cincinnati and Arizona voted no) to make instant replay a permanent fixture. Two more years remained on the current system, but the league wanted to buy new, high-definition equipment.

"It has been a long time coming," said Falcons general manager Rich McKay, a co-chairman of the competition committee. "It made sense to us - we thought this was the year to do it."

All but three NFL stadiums, at a cost of about $275,000 to $300,000 per team, will be wired for high-definition equipment before the season. The exceptions will be New York, Indianapolis and Dallas, where new stadium projects are under way. Those stadiums will be wired later.

A proposal to add a coach-to- player communication device for a defensive player was voted down 22-10.

ETC.: Shanahan said left tackle Matt Lepsis, who suffered a season-ending right knee injury at Cleveland and underwent microfracture surgery, is expected to be ready for minicamps in May and June. . . . Shanahan said he would consider trying to sign guard Cooper Carlisle and defensive tackle Michael Myers back if they don't get free-agent deals elsewhere. "Just see what the market value is; that's part of free agency," he said. "How close can we compete to what the market value is?" . . . Broncos tackle Erik Pears, who played for the injured Lepsis last season, was the fifth- highest earner in the league's performance- based pay system - bonuses put in place to add more money to players who find themselves playing more than expected. Pears earned a $258,422 performance- based bonus for 2006.