LEXINGTON, Ky. (AP) — Kentucky starting forward Alex Poythress will miss the rest of the season after tearing a knee ligament during practice in a devastating loss for the top-ranked Wildcats

The 6-foot-8 junior tore his anterior cruciate ligament in his left knee, the school said Thursday. A date for surgery has not been set, but recovery typically takes six to eight months.

Wildcats coach John Calipari called the injury "a big blow to our team. No one will be able to replace Alex and what he did for this team."

Poythress started eight games for the Wildcats (10-0), who face North Carolina on Saturday in a big test. He averaged 5.5 points and 3.8 rebounds in 20 minutes.

The muscular Poythress was shooting just 38 percent from the field but leads the team at the foul line, shooting nearly 86 percent. His 12 blocks rank third on the team while his 30 rebounds rank sixth.

Pursuing a title was a key motivation for Poythress to return for a third season after last spring's NCAA title-game loss to Connecticut.

Poythress was joined by 7-foot Willie Cauley-Stein on the front cover of this year's media guide. They are the most experienced players on a 10-deep roster featuring nine Wildcats at least 6-6, leading Calipari to implement a two-platoon system.

This is the third straight season Kentucky has lost a key regular.

Last spring, Cauley-Stein missed the final three games of the Wildcats' run to the NCAA title game with an ankle injury. Forward Nerlens Noel tore an ACL in February 2013, an injury that ultimately led to Kentucky missing the NCAA tournament.

Freshman guards Devin Booker and Tyler Ulis missed Wednesday's 56-46 victory over Columbia with unspecified injuries. Calipari said afterward he didn't know if they would play against the Tar Heels.

"How they will respond I really don't know," Calipari said in a school statement, "but I will do my best to be there for each of these kids."