LAKE FOREST, Ill. -- Chicago Bears defensive coordinator Vic Fangio said Thursday that Khalil Mack’s right ankle injury should not be used as an excuse for why the defense has underperformed the past two weeks.

"To think that one guy being out affects ... it may affect our overall performance, but it’s no reason for a guy over here and a guy over there to have a bad down because [Mack’s health is] sub-par," Fangio said.

"That’s just a fact. For anybody to use that as a crutch is just looking for a reason. Whether he’s out there playing at his best or playing at something less than his best because of an injury, it doesn’t affect the way the other 10 guys have to do their jobs. Now can the result be better? Yes, for the unit. But it still shouldn’t affect the way you do your job, and I just don’t buy that that’s the reason this guy is not playing as well or that guy is not playing as well."

An ankle injury has slowed Khalil Mack the past two games. Mark Brown/Getty Images

Mack hasn’t been the same player since he suffered an ankle injury in the first quarter of Chicago’s 31-28 overtime loss to the Miami Dolphins on Oct. 14.

Mack, the reigning NFC Defensive Player of the Month with four sacks, four forced fumbles, one fumble recovery and a pick-six in September, has been credited with only three combined tackles (zero sacks) over the past two games.

Despite barely practicing all week, Mack started last Sunday and played 54 of 64 possible defensive snaps against the New England Patriots.

But Mack, who had one tackle and zero quarterback pressures against Tom Brady, spent a good portion of the game dropping back into pass coverage.

Fangio insisted that Mack’s ankle problem did not impact the Bears’ game plan, but it’s fair to wonder whether Chicago would have taken more chances rushing Brady had Mack’s ankle been 100 percent.

"We had the plan to mix in some three-man rush with maximum drop because Brady likes to get the ball out quick and try to intermix that in there with everything else we do -- we rush three-, four-, five- even six- a few times -- just part of the plan to mix it up against a good quarterback," Fangio said.

The Bears face a similar dilemma as they prepare to take on the New York Jets on Sunday. Bears coach Matt Nagy said on Wednesday that Mack is unlikely to practice much during the week, but Mack, who’s never missed a game in his four-plus-year NFL career, will undoubtedly push to play on Sunday.

Do the Bears play Mack? Or do they rest him?

The Bears don’t have a break in the schedule until after they play the Detroit Lions on Thanksgiving.

"Well, he’s affected by [the ankle], but he hasn’t practiced this week so I don’t have a great feel for his current status, but he’s obviously not 100 percent but ... we’ll see," Fangio said.