Brazilian defender Gerson Vieira, who impressed during his two-year stint with Mumbai City, will now be seen in ATK colours in the upcoming Indian Super League (ISL).
The 25-year-old had a splendid debut season for Mumbai in 2016 when he made 14 appearances and helped them finish top of the table en route the playoffs.
He also captained the likes of Neymar, Philippe Coutinho, Casemiro, Alisson among others at the 2009 FIFA U17 World Cup.
"Vieira is a very versatile and exciting player. His talent and his leadership skills will impact the team in a very positive way. I welcome him to the ATK family," Steve Coppell, ATK head coach, said.