It would be an easier sell for Clippers coach Doc Rivers if Kristaps Porzingis didn’t tear his ACL three weeks ago to complicate the Knicks’ rebuilding program. But according to a former Rivers associate, it’s not far-fetched for the one-time Knicks guard to have interest in the team’s coaching job if Jeff Hornacek, who has one year left on his contract, is let go after the season. “Doc enjoyed his time there,’’ the former associate said. “He respects the city, he respects the organization.’’ The Knicks, who are scheduled to leave for Los Angeles after Wednesday’s practice, will face Rivers’ Clippers on Friday at Staples Center. Rivers has one year left on his contract that reportedly pays him about $10 million per season and he’d likely seek an extension in the offseason. Since he’s under contract, compensation in the form of a draft pick would be in order if Knicks president Steve Mills and general manager Scott Perry attempted to pursue Rivers. Ironically, Rivers, who won the 2008 NBA title as Celtics head coach, was said to be on thin ice earlier this season after losing his GM title to Lawrence Frank and having the team get off to a poor start. But the offseason loss of Chris Paul and the in-season blockbuster trade that sent Blake Griffin to the Pistons has the rebuilding Clippers alive and kicking at 31-27, one game out of the West’s eighth seed.