Enough, P.J. Fleck determined, was enough.

His Gophers football team lost 55-31 at Illinois on Saturday, one last, massive piece of mounting evidence to convince the coach that change was needed.

So, on Sunday, Fleck and defensive coordinator Robb Smith had a long conversation. The result: Smith was relieved of his duties and replaced in an interim basis by defensive line coach Joe Rossi.

“This is not about one specific game or one specific issue,” Fleck said Monday, explaining his decision to fire Smith, a longtime friend and colleague. “This is over a long period of time as you evaluate that. … Sooner or later you have to make a choice, and the choice is either stay or go a different direction.”

The direction Fleck wants to take the defense is away from this season’s disturbing trend. The Gophers (4-5, 1-5 Big Ten) gave up 646 yards of offense to an Illinois team that entered Saturday’s game as a co-tenant of the West Division’s basement. The Fighting Illini rushed for 430 yards, averaging 12.3 yards per carry, and scored seven touchdowns that covered an average of 47.6 yards.

Those stats were nothing new for Smith’s defense, which closed 2017 by giving up 39 and 31 points in shutout losses to Northwestern and Wisconsin, respectively. After a 3-0 nonconference start this year in which the Gophers gave up only 27 points, the defense started hemorrhaging yards and points in Big Ten play.

Beginning with Maryland’s big-play-fueled 42-13 romp, continuing in Nebraska’s 659-yard outburst in a 53-28 blowout and climaxing with Illinois’ cakewalk, Smith couldn’t find a fix for a defense that’s giving up 43.2 points and 507.7 yards in conference play.

“This is not something that you just decide to do [quickly],” Fleck said, snapping his fingers. “This is something that you do everything you can to fix it for as long as you can because he’s a very good football coach.”

Smith, 43, was in the final year of a two-year, $1.4 million contract that paid him $700,000 this season. Fleck made the decision on Smith in consultation with athletic director Mark Coyle, and he informed his staff and players Sunday afternoon.

“We talked about that it wasn’t because of them, it was for them,” Fleck said to his players in a half-hour meeting.

In Rossi, 39, Fleck sees a fresh start for the final three games of the season.

“One, it’s a new voice, it’s a different direction. It’s a different way somebody calls a game,” Fleck said. “This isn’t a wholesale change where our defense is going to look completely different schematically.”

Rossi also will take on Smith’s duties as linebackers coach. Pass rush specialist coach Marcus West now also will coach the defensive line, and defensive backs coach Jahmile Addae will coach the safeties. Quality control assistants Dan Collins and David Parker will coach more as well.

Fleck described Rossi, who served as Rutgers defensive coordinator in 2014 and ’15 and joined the Gophers in 2017 as a quality control assistant, as a “very hands-on coach, an incredible teacher.” Fleck said it was too soon to address his plans to find a permanent coordinator.

“Everything that I do, every decision I make is for those players moving forward and how we can find a way to continue to find success,” he said.