With 7-foot power forward Andrea Bargnani officially coming aboard July 10, the Knicks have had renewed discussions on a stricter minutes restriction next season for Amar’e Stoudemire, according to his agent, Happy Walters. The idea of a 20-minute nightly maximum with a prohibition on playing both ends of back-to-backs has been one of the ideas that has been discussed. “I don’t think anything has been decided,’’ Walters told The Post yesterday. “The doctors are still talking about that. But he’s not going to play a ton of minutes.’’ An extra-cautious approach on Stoudemire to have him on a minutes restriction lower than last season’s was a factor in the Knicks’ willingness to trade for Bargnani, feeling they needed another scoring big man. The Knicks played 18 back-to-backs last season, so that could potentially be 18 games Stoudemire misses. It’s not all that dissimilar to the Spurs’ treatment of the aging Tim Duncan. When Stoudemire returned from his first knee debridement surgery on Jan. 1, he was put on a 30-minute restriction, but coach Mike Woodson held him to the mid-20s. However, in March, Woodson twice played Stoudemire slightly more than 30 minutes during a four-games-in-five-nights stretch, after which Stoudemire headed for a second debridement surgery. When Stoudemire returned for the second round of the playoffs, doctors told Woodson not to play Stoudemire more than 15 minutes a game. When the season ended, Knicks general manager Glen Grunwald acknowledged Stoudemire could be on a minutes restriction next season after playing just 29 regular-season games. Now it’s even more prudent with Bargnani’s presence. The Knicks were willing to give up 3-point ace Steve Novak (who is limited otherwise), oft-injured center Marcus Camby, a 2016 first-round pick and two second-rounders for Bargnani, who himself had injury issues last season with a bum elbow, playing just 34 games.