UCLA leading tackler and linebacker Eric Kendricks had a big first half against Stanford, making nine tackles.
At halftime, he went to the hospital for tests on his kidney, a team spokesman told the Associated Press. It wasn't immediately clear what caused Kendricks' kidney injury.
Kendricks, a 6-foot, 228-pound junior, has made 56 tackles and one interception this season. His 150 tackles in 2012 led the Pac-12, though he only made honorable-mention all-Pac-12. NFL Draft Scout currently ranks him as their fifth-best inside linebacker prospect.