Smith played the remainder of the scrimmage, but figured something wasn't right after and approached team trainers. He was later diagnosed with the bruised kidney at Boulder Community Hospital, where he's spent the previous two nights.
CU officials said Monday Smith would remain at the hospital again Monday night for observations, according to head trainer Miguel Rueada. Smith is expected to be released Tuesday.
Head coach Dan Hawkins said Sunday it's unlikely Smith would play in the season opener Sept. 1 vs. Colorado State. But his status is not yet determined. Smith was among the top two performers at wide receiver during much of fall camp, offensive coordinator Mark Helfrich said.