The Broncos and guard Chris Kuper have agreed to a restructured contract that gives the six-year starter a strong chance to make the 53-man roster providing he proves to be sufficiently recovered from his left ankle injury.

The new contract will reduce Kuper’s 2013 salary from $4.5 million, zero of which was guaranteed, to $1.05 million, all of which is guaranteed. Kuper can also make an additional $1.7 million in game and playing time bonuses.

Had the Broncos waived/injured Kuper, they would have saved the $4.5 million, but he would have been entitled to a $1.05 million injury protection settlement. Thus, the base salary in his new deal. Kuper’s nonguaranteed salaries of $5 million in 2014 and $5.5 million in 2015 remain intact.

Kuper, though, hasn’t made the team yet, as his recovery is not assured. He participated in training camp for the first time this year Tuesday and spent time snapping the ball to Peyton Manning early.

Kuper spent time at second-team right guard during positional drills and sat out team drills, but he stayed on the field practicing snaps for about 10 minutes after practice ended.

Since Dan Koppen’s season-ending injury, the Broncos have had a competition at center between Ryan Lilja and Manny Ramirez. Kuper said he hadn’t played center in a game since college.

“I just kind of started today,” Kuper said of playing center. “I’ve done a little bit in the past, but nothing extensive.”

In the final game of the 2011 regular season, Kuper suffered a gruesome dislocated ankle injury that included other bone breaks and torn ligaments and tendons. Major surgery attempted to fix the ankle, but he started only five games last season when a plate holding his ankle together shattered.

He played with the shattered ankle plate in the Broncos’ playoff loss to Baltimore, then had a second major operation.

Mike Klis: 303-954-1055, mklis@denverpost.com or twitter.com/mikeklis. Caitlin Swieca contributed to this report.