Alex Len underwent surgery to stabilize a partial stress fracture in his left ankle, his agency Sports International Group announced on Friday.

Len will be sidelined four to six months, and will miss all pre-draft workouts leading up to the June draft. 

“The tough part about Alex’s injury is the timing,” Len’s agent, Michael Lelchitski said in a release. “Everyone who knows Alex knows that he would have been incredible in the pre-draft workout setting. However, Alex is one of the elite prospects with arguably the biggest upside of anyone in the draft. The most important thing is his long-term health.”

Len was projected by many to be a lottery pick in the upcoming draft.