Former Maryland center and anticipated NBA lottery selection Alex Len underwent successful surgery to stabilize a partial stress fracture in his left ankle, his agency Sports International Group announced Friday afternoon.

The surgery, agent Michael Lelchitski said, will preclude Len from all on-court activities leading up to the 2013 NBA draft, scheduled for Thursday, June 27, at Brooklyn’s Barclays Center. Len will be sidelined for four to six months, certainly through summer league and possibly through NBA preseason.

“The tough part about Alex’s injury is the timing,” 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.”

Dr. Robert Anderson in Charlotte performed the surgery. The release said Len was diagnosed with the partial stress fracture after declaring for the draft, though Coach Mark Turgeon said throughout the postseason that ankle injuries had hobbled the 7-foot-1 center.