Two first-half goals by Jorge Costa's Mumbai City sealed the fixture in favour of the hosts the Mumbai Football Arena.
We deserved more because we had many chances to score goals," Portugal said. "We committed a mistake for the first goal."
The Spaniard uttered words of praise for the two goalkeepers on the field - Amrinder Singh and Vishal Kaith. Pune's Kaith earned the team some saving grace when he saved a penalty by Lucian Goian at the fag end of the match.
"Mumbai had five chances to score and he also saved a penalty. We had a lot of chances as well. Their goalkeeper Amrinder played very well today."
Summarising his team's display against their Maharashtrian rivals, Portugal stated, "In football, if you don't score, it is impossible to win.
"We had good ball possession but we also had lots of chance in the opponent's area. I like this football but I also want my team to score goals."
Marcelinho's absence in the starting lineup, despite his availability after a one-game suspension, was puzzling. Portugal clarified, "Marcelinho had a problem with his calf this week and hence did not start. We did not want to take a risk with him."
Winger Ashique Kuruniyan also had to come off towards the end of the first half due to an injury.
"Ashique has a problem with the knee but I don't think it is a big problem. It is possible for him to recover for the game against Bengaluru FC."