Lucas Patrick’s switch to Center after McCoy left

McCoy calls the protections and audibles to the line's blocking scheme pre-snap. On top of that his blocking was literally the best Center in the league in the two game sample size we have.

That's just not a guy a team can replace midgame.

Not counting the end of the first half kneeldown, 17 of the Saints 72 yards of offense in the first half came from the three plays McCoy was in the game. That's 23.6% of the team's total first half yardage. The Saints had 99 yards of offense going into the fourth quarter. Essentially 17% of the Saints offense through three full quarters came on just three plays with McCoy in the game.

The offense literally hit a wall the moment McCoy left the game. It wouldn't be until the fourth quarter the offense would finally find some life, but then the defense would pull an all time classic Saints move.