Turns out that Michael Porter Jr.’s mysterious injury was much more serious than Missouri initially made it seem.

The school announced that the heralded freshman forward will undergo back surgery on Tuesday and will likely miss the rest of the season. The procedure, a microdiscectomy to repair damage to the L3-L4 spinal discs, has a projected recovery time of 3 to 4 months.

“I really appreciate the support of my family and the Mizzou Men’s Basketball program as I begin this process,” Porter said in a release. “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.”

A long, athletic forward who can score at all three levels, Porter entered the season widely considered one of college basketball’s three top NBA prospects along with Duke’s Marvin Bagley and Arizona’s DeAndre Ayton. Excitement for Porter’s college debut was sky-high at Missouri before the school’s Nov. 10 season opener against Iowa State, but he logged only two minutes before leaving the game as a “precaution” due to what the school deemed a hip injury at the time.

Concern about Porter’s health increased significantly four days later when Porter not only didn’t play but also wasn’t on the Missouri bench for a victory over Wagner.

Asked about the whereabouts of Porter that night, a Missouri spokesman told Yahoo Sports that the freshman forward watched the game on TV from the locker room because it was “easier on his leg injury than sitting at the team bench.” The Missouri spokesman said he could not clarify specifically what the injury was because he is “not privy to that information.”

Missouri coach Cuonzo Martin offered no further specifics that night or after Porter also missed two subsequent games. He classified Porter as “day-to-day” and insisted he knew nothing more about his best player’s status.

That the injury will likely end Porter’s season — and thus probably his college career — is a crushing blow to a Missouri program that hoped to experience a revival this season. The Tigers finished last in the SEC each of the past three seasons under former coach Kim Anderson.

Hired last spring to help Missouri regain relevance, Martin immediately made a shrewd move by hiring Michael Porter Sr. as one of his three assistant coaches. That enabled Martin to land the elder Porter’s two talented sons, Michael and younger brother Jontay, as part of a talent-rich recruiting class.

Missouri defeated Iowa State and Wagner without Porter, but the Tigers have found life without their star freshman more difficult in their past two games. They were clobbered by Utah in Salt Lake City and required a second-half comeback to edge Division II Emporia State on Tuesday night.

While enough talent remains for Missouri to avoid a fourth consecutive last-place league finish, the Tigers will be hard-pressed to finish in the upper half of an improved league or contend for an NCAA tournament bid.

Instead of a revival, Missouri is likely going to be left pondering what might have been.