Projected 2nd-rounder Charles Matthews tears ACL during Celtics workout

Former Michigan guard and draft hopeful Charles Matthews suffered a torn ACL during a recent workout with the Boston Celtics, his agent Adam Pensack told ESPN's Jonathan Givony.

The 22-year-old will undergo knee surgery in Chicago, with a timetable for his return set afterward.

"Injuries are tough, but Charles is an extremely hard worker and will be back stronger than ever," said Pensack. "He had a series of outstanding workouts lately and has helped himself. Charles will continue that momentum when he returns to action."

Matthews was projected to go in the second round as a high-upside defender.

He averaged 12.2 points, five rebounds, and 1.4 assists on 43.1 percent shooting during his junior year with the Wolverines.

The NBA draft takes place June 20.