Dyson scored 14 points vs. San Diego in the first round NCAA game during his sophomore year, which was a little above his 12.5 ppg scoring average for the entire season. We lost that game by one point in OT. It was clearly a team loss, and certainly not a game where you could point to Dyson as the primary reason for the L. Then you cherry pick one bad game vs USF (actually, it was against St. John's in the BET) a season later, in which he had nine turnovers, as a predictor of how he would have played against Michigan State a year before that? That also wasn't the last game of his career, as he played in two NIT games afterward, a win over Northeastern in which he was the game high scorer with 18 points, and a loss to VA Tech on the road, in which he scored 15 points. By your logic, I could cherry pick his career high 32 point performance vs. No. 1 Texas during his senior year as the reason he would have led us to the national championship in 2009. That's just as dumb as your logic.
In three postseason tournament games, 1 NCAA and 2 NIT, the guy averaged almost 16 ppg, which was slightly more than his overall career average at UConn of 14.4 ppg. I think you need to look elsewhere for evidence that he wouldn't likely have contributed vs. Michigan State.