With the start of free agency just 31/2 weeks away, the New Orleans Saints have begun the process of getting under the expected 2013 salary cap of about $121 million.

ESPN.com reported Friday that linebacker Curtis Lofton, the team’s leading tackler last season, has restructured the contract he signed a year ago when he came over from the Atlanta Falcons.

By turning a $5 million roster bonus into a $5 million signing bonus, which can be pro-rated over the final five years of the six-year deal he received last spring, Lofton’s cap hit for 2013 will drop from from $7.1 million to $3.1 million.

That $4 million savings is just a start for the Saints, however, as they were reportedly more than $20 million over the expected 2013 salary cap recently.

According to NFL Players Association figures, Lofton — who was the Saints’ leading tackler in 2012 and is expected to be one of the inside linebackers in their new 3-4 scheme — will earn $1.1 million in base salary this season.

Lofton, a 6-foot, 241-pounder who will turn 27 in June, was credited with 157 total tackles and had one sack. He also forced two fumbles, recovered two fumbles and broke up 10 passes.

The Saints will have to restructure more contracts, as they did last offseason, or release some players to get under the expected $121 million cap before the league year begins with the start of free agency on March 12.

Among the higher-profile players who could be asked to restructure their deals for cap relief are quarterback Drew Brees, guard Jahri Evans, cornerback Jabari Greer, linebacker Jonathan Vilma, safety Roman Harper and defensive end Will Smith.

Vilma, Evans and Smith were among the players who restructured last offseason.