BREAKING: Atlanta United sign Giorgos Giakoumakis from Celtic. (@fabriziorom) The 28-year-old striker has 9 goals in 28 games for Celtic this year and is two years removed from scoring 29 goals in 33 games in the Eredivise. Giakoumakis arrives as a DP and will sign a 3 year deal with option. He is on his way to Mexico now to meet the team. Welcome to Atlanta, Giorgos!