 Head coach Mike Smith named Grimes and newly acquired free agent Dunta Robinson the starting cornerbacks to begin the 2010 regular season.On October 17, 2010, Grimes collected a season-high 12 combined tackles (ten solo) and a pass deflection in the Falcons' 31–17 loss at the Philadelphia Eagles in Week 6.In Week 13, he made seven combined tackles, a career-high six pass deflections, and intercepted a pass by Josh Freeman during a 28–24 victory at the Tampa Bay Buccaneers.