Atlanta United acquired JJ Williams from Birmingham Legion FC in the USL to replace Josef Martinez.
Martinez was ruled out for the season with a torn ACL.
"JJ is someone that had been on our radar over the offseason and we're pleased to add him to our roster. He is coming off a strong season with Birmingham and will provide additional competition to our attack," said technical director Carlos Bocanegra.
The 22-year-old played in 7 matches last season as a rookie with Columbus.