Rays starter Alex Cobb has been diagnosed with a mild concussion, according to MLB.com.

Tests came back normal for Cobb, who left Saturday's start against the Royals in the fifth inning after being struck in the head by a line drive. He is expected to remain in the hospital for further examinations. Cobb surrendered two runs on four hits and three walks while striking out three in 4 1/3 innings of a no-decision before leaving the game on a stretcher.