ENGLEWOOD, Colo. --The Broncos needed more experience up front. A two-time Pro Bowler and All-Pro from as recently as 2013 was still on the market.

The collision of those two circumstances spurred the Broncos' decision to add Mathis, who agreed to terms on a one-year contract Tuesday afternoon. Mathis provides an instant injection of elite recent performance to an offensive line that on Saturday in Houston started three starters who had never played a regular season snap.

With Mathis aboard, he team has -- on paper, at least -- perhaps the league's best set of guards. Mathis worked at left guard in Philadelphia; he and right guard Louis Vasquez were All-Pros together as recently as 2013.

The Broncos could still go into the season with at least two starters who have never played an NFL regular-season snap. But at least now the team has two pillars around which to construct a quality offensive line -- just as they possessed going into OTAs, when the line was set to be built around Vasquez and left tackle Ryan Clady before the latter succumbed to a torn anterior cruciate ligament.

For the last two years, Mathis has been among the league's best. A classic example of a late bloomer, he started just 22 games for three teams between 2006 and 2010.

His trajectory began its ascent in 2009 when he started seven games for the playoff-bound Bengals, but it was in Philadelphia that he finally emerged as one of the sport's finest up front. He was the league's highest-rated guard by ProFootballFocus.com in 2011, 2012 and 2013; last year, he was No. 2 because he missed seven games because of a sprained medial collateral ligament.

Despite spending nearly half of the 2014 season on recallable injured reserve before his return, the 33-year-old Mathis made his second consecutive Pro Bowl appearance at the end of the season after allowing just two sacks in nine games.

Philadelphia's decision to release Mathis in June stunned the league. At the end of that month, he was rated as the top free agent on the market by a wide margin.

Denver's interest in Mathis came as little surprise given that the team talked to another offensive lineman, eight-year veteran offensive tackle Jake Long, just before training camp began. The Broncos passed on Long, but Executive Vice President/John Elway made it clear then that the door was not closed on potential additions to bolster the offensive line.

"We'll continue to look at all our different options through training camp and as we go," Elway said July 30. "I'm never counting anything out."

In the short term, the bulk of the change is likely to be felt by fourth-round pick Max Garcia, who moved onto the first team at left guard for practice Aug. 6 and has remained there for two weeks.

But it's important to remember that Garcia was not drafted simply to play left guard. His versatility allows him to line up at any of the three interior spots, and he is in good shape to become the swing backup for the center and guard positions. If he settles in at that role, Garcia could be active on game days, and potentially the first reserve to enter if injury strikes a starter. He remains firmly in the Broncos' long-term plans.

But for the Broncos, the opportunity to add a current Pro Bowler was too much to resist. Mathis makes the Broncos better now, and given what Garcia will learn from him, he can make the Broncos better in the future beyond the length of his one-year contract.