Baltimore Ravens rookie wide receiver Mark Clayton strained his left hamstring and was held out of practice, although the injury is not considered serious.
The first-round draft pick from Oklahoma was hurt running a pattern.
"I felt something and slowed down," said Clayton, who laughed while insisting he will ready for the season-opener against Indianapolis.
Clayton didn't drop any passes and made a strong impression during Baltimore's two-day rookie camp. The Sooners' all-time leading receiver is to start opposite Derrick Mason.