The deal haddn't been finalized yet, but those close to Beuerlein and the Broncos said it would give Beuerlein additional financial incentives should he end up stepping into the starting role at any point.
Beuerlein, who turned 38 on March 7, has one year remaining on his four-year deal. It calls for him to earn $1 million in base salary.
Beuerlein indicate he was 99 percent certain of retiring after the Broncos signed free-agent Jake Plummer to a six-year $40 million deal last month. But a visit by Shanahan to Beuerlein's North Carolina home apparently convinced him to change his mind.
Shanahan knows Beuerlein would be a steady influence on Plummer, and provide veteran leadership to the team.
Shanahan insists he hasn't heard officially from Beuerlein. But even if he already has both two proven QBs on his roster, he didn't rule out taking one high in the draft.
"It depends on who's there," Shanahan said. "We weren't planning on drafting a running back last year but (Clinton) Portis was there and because of his talent, we picked him. It's the same thing with the quarterback position. You never know."
The Broncos pick 20th overall. Shanahan said he expects three quarterbacks will be taken in the first round.
Broncos players, meanwhile, will get their first up-close look at their new signal-caller.
The team's offseason conditioning program starts March 31, and Plummer has indicated he will be a participant.
One person who won't be there is Brian Griese. He is recovering from shoulder surgery, and also will be dumped after June 1.
Critics question whether the interception-prone Plummer is the answer for Denver, which has missed the playoffs three of the past four seasons and has not won a post-season game since John Elway retired.
Shanahan was optimistic. Though he didn't make any comparisons this time to Joe Montana as he did with Griese, he offered another analogy.
"Why was Steve Young not very good at Tampa Bay? Why wasn't he," Shanahan asked, in citing prominent quarterbacks who have gone on to success with other teams.
"Was it the system or was it the offense and defense?
"Here's a guy that will be in the Hall of Fame (after a career with San Francisco), but was 4-28 in Tampa Bay and had 11 touchdowns and 20-something interceptions for them. "