According to the MSU Football Twitter feed, quarterback Andrew Maxwell suffered a sprained knee in the first spring scrimmage and will be sidelined for at least a week. MSU said Maxwell is questionable for the Spring Game on April 28.
That leaves redshirt freshman Connor Cook as the No. 1 quarterback with fifth-year senior Peter Badovinac and redshirt freshman Tommy Vento has the backups. Spartan Tailgate's Dan Kilbridge said Dantonio told reporters the injury occurred while Maxwell was leaving the pocket and "sort of fell backwards."
This also might explain why the defense dominated the scrimmage as much as they did.
For Maxwell, this appears to only be a minor setback. While getting more reps with the young receivers is important, it doesn't seem to be a major injury. For Cook, it will be an big opportunity to develop chemistry with the young receivers, whom Cook could be throwing to as the starter in two seasons. The coaches have liked what Cook has shown in practice over the last year. Incoming freshman Tyler O'Connor likely will be the No. 3 quarterback when he comes to MSU this summer.
Looking at the big picture, this will be a chance for MSU to develop a reliable backup. In five seasons, Dantonio has only had to deal with a serious injury to his starter in 2009, when he had two No. 1 quarterbacks in Kirk Cousins and Keith Nichol. (I define "serious" as not being able to start the next game). Sometimes you forget the backup quarterback is only one play away from taking over the reins of the offense.
Injuries happen in the spring. This one just gets more attention because it's the quarterback.
While the Spring Game might not be as exciting without the starting quarterback, the next two weeks will be a good opportunity for Cook to take a step forward in his development, which will help MSU should anything happen to Maxwell again.