The Athletics placed Clarke on the 10-day injured list Wednesday with a bone bruise in his right foot.
Clarke didn't start either of the previous two games, though he appeared on defense in Tuesday's win over the Mariners. He will be eligible for activation at the beginning of May, but it's unclear whether he will be ready to go at that time. Zack Gelof started the last two contests in center field for the Athletics and Lawrence Butler will shift over to center in Wednesday's game in Seattle.