(CBS) Missouri freshman forward Michael Porter Jr., a projected top-three pick in the 2018 NBA Draft, will undergo back surgery Tuesday and is expected to miss three or four months, the school announced.

Porter, 19, played just two minutes in the Tigers’ season opener before pain forced him to the bench. He’ll undergo a microdiscectomy of the L3 and L4 spinal discs. He’s expected to make “a complete recovering,” the school said.

“I really appreciate the support of my family and the Mizzou men’s basketball program as I begin this process,” Porter said in a statement. “I’m thankful for all the kind words and messages I’ve received from fans. Those mean a lot to me. I cannot wait to be completely healthy and playing the game I love, once again.”

As the Bulls have embarked on a rebuilding process and started 3-11 this season, Porter is a prime prospect for them to evaluate. That evaluation process will now have to wait until next spring.

If Porter makes a full recovery in the expected timeline, he’ll still have several months to get in shape ahead of the NBA Draft next June and work out for teams.