Iman Shumpert had a second left knee operation over the summer, the Daily News has learned, and it is unclear if the unreported surgery could affect his trade value — with the desperate Knicks trying to package Shumpert in a number of proposed deals, including one for Boston’s Rajon Rondo. According to a source, Shumpert had arthroscopic surgery on his left knee last July that the Knicks never reported. In September, the Daily News reported that Amar’e Stoudemire had knee surgery over the summer, which the Knicks also elected not to make public. Shumpert originally tore the ACL and meniscus in his left knee against the Miami Heat during Game 1 of the 2012 playoffs. Shumpert didn’t return until Jan. 17, 2013, and has felt soreness on several occasions, including the Knicks’ second-round playoff series against Indiana. In October, Mike Woodson cryptically said that Shumpert had “battled this summer with some of his injuries” and added that Shumpert had experienced knee pain but left it at that. Despite missing a few days of training camp due to what the Knicks claimed was a shoulder injury, Shumpert has been available for all nine games this season but has clearly fallen out of favor with Garden chairman James Dolan and Woodson.