DJ Hayden has missed practice with the Oakland Raiders after injuring his groin during Wednesday's session.
The rookie cornerback was unable to take to the field yesterday, despite returning to practice earlier in the week after sustaining the initial injury.
Head coach Dennis Allen told reporters: "He strained his groin [on Wednesday]. He was able to finish practice.
"I wasn't really aware of it until after I got done in here with you guys, but he wasn't able to go today. We'll have to evaluate him and see how he's doing and see how quickly that thing responds."
Hayden has 23 tackles, a forced fumble and an interception so far this season.