The 6-foot-3, 217-pound athlete declined to put a percentage on just how solid his pledge is.
"I don't think there is strength in a commitment," Isaac said, "you are either committed or you're not, and obviously I am."
Isaac said there are several schools that still contact him.
"I have heard from schools, but that's been throughout my commitment," Isaac said. "Even before USC had a season that didn't go according to plan. There are a lot of Midwest schools like Notre Dame, Michigan, Ohio State, but none of them have contacted me more than the others.
Isaac said he was unsure if he would be taking any official visits after the Under Armour All-America Game.