After the game, asked if there was one play he could have back, he confidently named that one.
"The Mumphery one," he said. "He got behind the defense and that's a throw I have to make."
This Saturday, Mumphery found himself open against Illinois and this time Cook didn't miss, hitting the junior wide receiver in stride for a 47-yard touchdown.
It was the last of his 15 completions in just 16 attempts and a fulfillment of what he told coach Mark Dantonio just a week ago when he struggled against the Boilermakers: "Don't worry."
"Coming off the performance that I had last week, obviously I was upset and really focused on things I need to get better at in practice," Cook said. "I just always believe in myself, have faith in myself and I told him, ‘Don't worry, we'll be okay.' I have full belief in myself."
Dantonio said it wasn't new to see Cook respond like that and that it is part of the growing process for the young quarterback.
"When you're a young player, you have a chance to sit back, regroup, re-establish yourself and move forward," he said. "He's got tremendous talent. He was off a little bit throwing the football last week, but he's able to regroup himself and move forward."
Not only did Cook move forward, he set a Michigan State record with a 93.8 completion percentage.
The sophomore said that is a testament to the fact he didn't down on himself or dwell in the past.
"I put stuff behind me and I move forward," he said. "I always have confidence in myself and I always believe in myself no matter what. If I have a really crappy before last week, that I can come out this week and put it all behind me and have a good game."
So what made the difference in a matter of seven days for Cook?
"I think it was great play calling," he said. "The run, too, helped out a lot with play-action passes and opening up the pass game because we were able to run the ball so well on them.
I really don't know … maybe it was the wind."