UCLA LB Myles Jack (knee) may eventually require microfracture surgery on his knee, which has an osteochondral defect, where bone and cartilage are beginning to separate. If or when the bone and cartilage fully separate, microfracture surgery will enter the possibilities. ‘Is he a four-year player or a 10-year player? But technology is better now. So we really don’t know,’ a top talent evaluator said.