Atlanta United have acquired attacking midfielder Gonzalo "Pity" Martinez from River Plate, the club announced on Thursday.
Martinez, 25, was named South American Player of the Year for 2018 as he helped lead River to a Copa Libertadores title over archrivals Boca Junior in the final.
"We're excited to announce we've secured Gonzalo to a long-term contract with our club," said Atlanta United Vice President and Technical Director Carlos Bocanegra.
"Recently named as the best player in South America in 2018, Gonzalo is an attacking player who can play wide or centrally. His abilities complement our style of play and we expect him to make a smooth transition to MLS."
Martinez, who had told reporters after the Libertadores final that he was moving to Atlanta, will be formally introduced as an Atlanta player on Friday.
"I'm very excited to come to Major League Soccer and to join Atlanta United," Martínez said. "The club has shown a lot of trust in me and I'm looking forward to working with Frank de Boer and my teammates to continue making history at the club."