Broncos coach Josh McDaniels decided to end the suspense early heading into next month's training camp.
But McDaniels apparently liked what he saw in Orton's assimilation to the offense over the past several months to give the three-year veteran the edge for now, stressing there was still time for Simms to take away the job.
Also, wide receiver Brandon Marshall was again a no-show at minicamp, one day after a face-to-face meeting with team owner Pat Bowlen and McDaniel Friday night.
Marshall is unhappy with both his contract and what he considered a misdiagnosis of a hip injury last season and has been working out on his own in Orlando, Fla.
"Hopefully it'll all end up the way we want it to end up with him on the field here," McDaniels said. "If and when Brandon's out here with us, it'll be great." Bowlen declined comment.
McDaniels informed Orton of the quarterback news Friday night, and the former Chicago Bears quarterback took all the snaps behind the first-team offensive line during Saturday's practice.
"There's a lot of difficult aspects about what we ask our quarterback to do in our offense and Kyle has really grasped some of them more quickly than Chris did," McDaniels said in explaining the move after the second day of a three-day minicamp at the team's Dove Valley headquarters.
"I just think it puts them in a little bit of a pressure situation where now one of them has it and has to keep it and the other one has to get it," McDaniels added. "They're still going to compete with each other and I expect the competition to be the same that it's been. They both have great attitudes and know that nothing's determined in June."
Orton completed 272 of 465 passes for 2,812 yards with Chicago last season, throwing 18 touchdowns and 12 interceptions. He's appeared in 33 games during his three-year career.
Like Simms, he's had to adjust to a new team and offense. But he's also demonstrated less rust than Simms, who hasn't played since Week 3 of the 2006 season due to complications from a ruptured spleen while playing for the Tampa Bay Buccaneers.
"I'm obviously really excited," said Orton, who was a key piece to the Cutler deal that also included four high draft picks. "It's really just the beginning for me in this offense and hopefully I'll continue to improve every day and get the offense where we need to be come the season."
Orton said that it's been difficult trying to find a comfort level in McDaniels' offense and that he's had good and bad plays along the way.
That was evident Saturday, when Orton had interceptions run back for scores by cornerback Jack Williams and outside linebacker Robert Ayers. But Orton also lofted a perfect sideline pass into the arms of rookie running back Knowshon Moreno in tight coverage.
"Kyle's extremely underrated," Simms said. "I've always felt that way. He was underrated in college and with the Bears. He throws the ball very well. He's a smart guy. He's a big guy. There's a lot of plusses with Kyle."
Simms wasn't surprised that McDaniels decided to make the news public now instead of waiting until training camp.
"We can't both go in there as 1-A and 1-B," he said.
Information from The Associated Press was used in this report.