BOCA RATON, Fla. — John Elway walked into huddles with Prestone running through his veins. With the crowd at full throat, Elway navigated goosebump drives for improbable victories.

Broncos president Joe Ellis says Elway exercises similar calm as a general manager. The Broncos have endured a litany of losses this offseason, their roster raided in free agency. Only one move came as a surprise: the loss of quarterback Brock Osweiler.

The Broncos thought they had a good relationship with Osweiler. Figured they could iron out a deal. Then he stopped returning their calls. And it became obvious that he was looking elsewhere. When the Broncos offered a four-year, $64-million deal with more than $30 million guaranteed and didn’t hear back, they knew they were out. They took a deep breath, relieved Osweiler didn’t say yes to an amount the Broncos were not comfortable reaching for a quarterback with seven career starts.

They are starting over at quarterback. Only the most important position in the league. Elway and Gary Kubiak huddled, and Elway moved to acquire Mark Sanchez. He brings experience in Kubiak’s offense from his days at USC, and provides a safety net, preventing an overreach in any trade or signing. Sanchez reacted to this opportunity by ensconcing himself at the Broncos facility, studying film, working out. He will be ready to compete for a starting job. But with whom?

Colin Kaepernick remains the most attractive option. He played in one Super Bowl and was one Richard Sherman batted pass away from starting another one. The Broncos know him, and like him. What makes Elway a top executive is that he exercises discipline. The easy move would have been to send a second-round pick to San Francisco weeks ago for the disgruntled Kaepernick, who has requested a trade.

Why? Cleveland is out, having signed Robert Griffin III. The Jets are the only other team mentioned in connection with Kaepernick. And most in the industry believe the Jets will eventually work out a contract with free-agent Ryan Fitzpatrick.

That leaves the Broncos with leverage — and options. They can stare down the 49ers, see if San Francisco will guarantee $11.9 million of Kaepernick’s salary on April 1. San Francisco coach Chip Kelly insisted last week “You don’t cut talent” when asked about releasing Kaepernick (though his record with Philadelphia of shedding DeSean Jackson suggests otherwise). Denver’s preference would be to pursue Kaepernick as a free agent, on its terms. As it stands, the Broncos don’t have to offer more than a fourth-round pick when Kaepernick’s trade market remains limited at best.

If the 49ers call the Broncos’ bluff and guarantee Kaepernick’s salary, the draft becomes the next potential power play. San Francisco could hold onto the quarterback until it picks in the first round, possibly with California’s Jared Goff sitting there at the seventh pick.

Kaepernick to challenge Sanchez makes sense.

The other options are less sexy, backups such as Josh McCown, Brian Hoyer, Nick Foles and the intriguing Mike Glennon. Elway’s ability to land a pair of offensive tackles in Russell Okung and Donald Stephenson opens up all avenues in the draft — from Mississippi tackle Robert Nkemdiche to quarterbacks such as Paxton Lynch, Dak Prescott and Connor Cook.

The clock is ticking, pressure mounting. You get the feeling Elway has them right where he wants them.

Troy E. Renck: trenck@denverpost.com or @troyrenck