Grimes had surgery on his right knee last week and is expected to miss two to four games. Dominique Franks could make his second straight in the Falcons' banged-up secondary.
Another cornerback, Kelvin Hayden, has missed two straight games with a toe injury. And safety William Moore hasn't played the last four weeks because of a quadriceps and groin injury. Coach Mike Smith says "when you're dealing with two major muscle groups, you want to make sure that he's ready to go before we put him back out there."
When Moore returns, he'll have to win back his job from James Sanders.