Colorado State could be without head football coach Mike Bobo when it opens the season against the University of Hawaii in 11 days.

The Rams, who host the Rainbow Warriors on Aug. 25 in Fort Collins, Colo., said in a statement Monday that Bobo has been hospitalized and is “… undergoing medical evaluation after recently experiencing numbness in his feet.”

Neither Bobo nor athletic director Joe Parker gave an indication of how long the coach might be out.

Bobo underwent knee replacement surgery in the spring and had expressed “growing concern” about the numbness, the Loveland (Colo.) Reporter-Herald said.

In a statement, Bobo said, “I recently began to experience numbness in my feet. After our second scrimmage on Saturday night it was determined by doctors that I should be admitted to the hospital to undergo further testing.”

CSU did not immediately name a temporary replacement, but quarterbacks coach Ronnie Letson, who followed Bobo from Georgia to the Rams, is listed as the assistant head coach.

UH coach Nick Rolovich said, “I tried to call him and left a message. I think he is a good football coach, a great man and I appreciate him being in this conference. I wish him nothing but the best whatever the situation he is dealing with.”

Bobo said, “I feel very encouraged by the test results to this point and hope to have some answers soon. I also feel very encouraged about our 2018 CSU football team. We have excellent coaches and excellent leadership in this program, and I have full confidence that they will continue to have tremendous preparation on and off the practice field for as long as I must be away. My family and I appreciate all of the great care and support we are receiving.”

Parker said, “I want to express my care and concern for Mike Bobo and his family at this time. Our first priority is to focus on Mike’s health and well-being, and to support that process in every way we can. I share Mike’s confidence that we have tremendous leadership in our football program, and that the coaching staff will continue to successfully guide the team through practices and meetings while he is away.”

Bobo is 21-18 in three seasons at CSU.