His ISL 2015 appearance lasted 72 minutes as he sustained an injury that kept him out of the season but after returning to fitness, he joined Rio Ave FC in the Portuguese top tier and scored five goals to help them qualify for Europa League.
"It's great to be back. I am fully fit now and it feels fantastic. Hope I can improve my last year's performance and help the team in becoming champions," Postiga, who represented his country in two World Cups and three European championships and helped Portugal reach the 2004 Euro final, said.
Despite the injury, the Portuguese forward made an impact last year scoring twice in ATK's 3-2 win over Chennaiyin FC in the opening match.
Welcoming Postiga back to the franchise, ATK's Canadian forward Iain Hume, one of the leading scorers of the tournament, said: "Two goals from one match, it's not a bad record after all. If he can add up to that it can be a great for the team."
In Postiga's absence last season, Hume, who had switched over from inaugural edition runners-up Kerala Blasters FC, had carried the extra responsibility but the Scottish-born Canadian did not disappoint as he scored 11 goals.
Despite scoring 16 goals from two seasons, Hume is yet to win the ISL silverware which would be his first priority in the third edition. "As far as the target goes, there's only one target to lift the trophy on the last day. I missed out in the first season (for Kerala Blasters). And last time, we were arguably the best team in the league but we lost one bad game and it killed our season. We are looking to go one step further and get past the semifinal. I'm keeping my fingers crossed," Hume said of their semifinal loss to Chennaiyin FC last season.
"There's no reason why we can't the results. We want to start off well in the first game and continue that to the last game," Hume said.