The Buffaloes plan to seek a medical hardship year for the freshman.

Mono is a virus that typically causes flulike symptoms. It can also cause glands to swell and Hawkins said Tuesday that Kasa has an enlarged spleen.

Kasa missed the first three games of the season with a partially torn MCL in his knee, only to return against West Virginia. He had two tackles in four games, before sitting out the Missouri contest last weekend with the illness.

The Buffaloes also will be without receiver Anthony Wright for the Texas A&M game Saturday after he injured his knee against Missouri.