Eric Mangini, the former Jets coach who seemingly blew the whistle on Spygate, set the record straight in an interview with the New York Post Tuesday.

“Spygate is a big regret,’’ said Mangini, the former Patriots assistant and onetime friend of Bill Belichick.

Mangini knew of the Patriots’ tapings from his time with the team (2000-05), and alerted Jets security that the Patriots could be taping the Jets’ signals during their game Sept. 9, 2007, at Giants Stadium.

Mangini simply wanted the Patriots to stop taping. He never thought it would get reported to the NFL. Enter GM Mike Tannenbaum, who did just that, and Spygate was born.

“There was no great value in what they were doing,’’ Mangini said. “It wasn’t worth it. It wasn’t worth it to me personally. It wasn’t worth it to the relationship.’’

Mangini’s relationship with Belichick died that day.

“I cared about him,’’ Mangini said. “I didn’t want to hurt him. I didn’t want to hurt the Patriots. It wasn’t like I was thinking I really want to get these guys. My thought was I don’t want to put my team at a competitive disadvantage, no matter how small.’’

Texans’ Watt placed on IR

J.J. Watt was placed on injured reserve, which means he’ll be out for a minimum of eight weeks after reinjuring his back. ‘‘You can never replace the best player in the NFL,’’ coach Bill O’Brien said. The team is still exploring the injury and it’s unclear if it will require surgery . . . The Seahawks signed C.J. Spiller to a one-year contract after the veteran running back was released by the Saints Sept. 13. Seattle has been thinned at running back after Thomas Rawls went down with a crack in his left fibula and C.J. Prosise has been out since breaking a bone in his hand in the opener against Miami . . . Dez Bryant has a hairline fracture in a bone in his right knee, though the Cowboys receiver might not miss a game. Bryant didn’t practice Wednesday, three days after getting hurt in a win over the Bears, and the same day the team got back results of an MRI . . . Bears quarterback Jay Cutler returned to practice on a limited basis after missing a game because of a sprained right thumb . . . Jets coach Todd Bowles said receiver Eric Decker was ‘‘probably’’ going to have an MRI on his injured shoulder and his availability for Sunday’s game against the Seahawks is uncertain.