"He visited this weekend," Keatts said. "Obviously he got back and made his decision yesterday."
The Mountaineers beat Tulane and a host of high-profile mid-major programs to land the Maryland native.
Alexander is a talented athlete. In fact, he's one of the better athletes on a strong Hargrave team. The Mountaineers figured him to be an excellent fit for their style of play.
"I think he's tailor made for the way John Beilein and his staff play," Keatts said. "In my six years at Hargrave he may be the most intriguing guy that I've ever coached. He does some things that you can see where down the road he's got a chance to be good.
"I think right now his strength is his athletic ability and his outside shot."