Peterson signed with Atlanta United as a free agent after five seasons with Sporting KC. He was added to be a key backup at either wide midfield position.

Partially because of Peterson’s injury, manager Gerardo Martino has been forced to play Yamil Asad through most of the games, though Chris McCann did come in for him in the final minutes of last week’s 1-0 win over Orlando City.

Peterson has three appearances with the Five Stripes this season. He has scored one goal, increasing his career total to 23 in 249 regular-season appearances dating to his debut with Colorado in 2006.

Peterson, 31, said he is still working on getting his fitness back to what he wants.

“At this point, it’s really about getting used to the ball, getting the touch back and getting that physical base that I need,” he said.