Mankins is regarded around the league as one of the best guards and one of the best linemen. He's had a tough year (and you could speculate further about his new contract, but I don't believe it), but we've looked at how difficult his schedule has been. Whether he's been playing a Pro Bowler or a Pro Football Focus star, he's been squaring off against one of the elite players in the league.
This week won't get any easier. The Broncos feature Broderick Bunkley, one of the best run defending defensive linemen in the league. Bunkley plays only a half to a third of the snaps as he's primarily just a run defender. His job is to force opposing teams into 3rd and long situations- and he's one of the best in the league at his job.
That's where the importance of Mankins comes into play. If Mankins is hobbled or is unable to play, then Bunkley will get to play against back-up Ryan Wendell (who played extremely well in Week 17) or Donald Thomas (who played pretty well in Week 16). Should Mankins be unable to play, the generally untested and undersized 6-2, 290 lbs Wendell will have to face off against Bunkley and the Broncos ferocious defensive line.
Even though Mankins has had a down year, would you rather Mankins face Bunkley, or would you be fine with Wendell or Thomas?
Personally, I think a healthy and prepared Wendell might be able to do the equivalent job a seriously injured and hobbled Mankins would be able to do. 75% Mankins = 100% Wendell. Everyone is reporting that Mankins was limping around, which is not a good sign with the game only a day away, so he's clearly not at 100%.
Not to look beyond the Broncos, but if Mankins is under 75%, the Patriots should sit Mankins. Mankins could do serious damage to his knee and it might take longer for it to heal. If he's able to play at a high level, then by all means he should take the field. If not, he should sit and rest up for the next game (hopefully it's next week).
So my question to you all: Would you play Mankins, even if he's injured, or how would you arrange the Patriots offensive line?