It was a miserable weekend for Bill Belichick proteges

Week 15 was a rough one for former and present Bill Belichick trusted lieutenants.

While New England offensive coordinator Josh McDaniels’ game plan fell flat in a loss to Pittsburgh, former Patriots defensive coordinator Matt Patricia, clearly frustrated, dropped an F-bomb during a postgame radio interview Sunday after the disappointing Lions fell to 5-9 with a 14-13 loss to Buffalo.

“Look, for us, it’s not different. We go out, we compete, we try to win and we try to f–king get better every week,” Patricia said on WJR following Sunday’s loss to the Bills.

One year ago, Jim Caldwell was fired by Detroit after posting a 9-7 record, but the Lions have lost six of their last eight games under Patricia to seal their 16th playoff miss in the past 19 seasons.

Meanwhile, McDaniels turned down an offer to be the Colts’ head coach this season to remain with the Patriots, but New England has dropped consecutive games in December for the first time since 2002 following Sunday’s 17-10 loss to the Steelers.

“We’re just obviously not playing well enough to win,” Tom Brady said after the Pats fell to 9-5 and suffered a fifth loss for the first time since 2009. “Just missed opportunities, too many plays where we got opportunities to do stuff with it and we don’t. It’s football. Wish outcomes were different. But just have to get back to work.”

The Colts have improved to 8-6 with back-to-back impressive wins over Houston and Dallas, including Sunday’s 23-0 blanking of the NFC East-leading Cowboys.