Chhetri played a stellar role in India's 4-1 rout of higher-ranked Puerto Rico in the international football friendly here last night.
"Sunil Chhetri is the talisman of this team. He is a wonderful player. He has been scoring goals for the last 10 years. I keep teasing him, saying 'your time is almost done', but he's not having that. He says he has another 4-5 years in him," said Constantine after India's key player set up two goals and scored one in a dazzling display of creative football at the Andheri Sports Complex stadium that hosted its first major game.
"But look, he keeps himself in great shape. He is one of the leaders of the team, the captain. And as long as he's fit, he plays," said the Englishman after India, ranked 152 on the FIFA table, humbled Puerto Rico, ranked 114, by coming back from a goal down.
Constantine also said that Chhetri, the regular captain who gave away his armband for the game in favour of Norway-based goalie Gurpreet Singh Sandhu, can play in multiple positions up front.
"A player of his calibre, you have to find the space for him. For me, his place is behind the striker. He brings other people into the game. He has an eye for goal, he sees the pass, and he works. It's not like he's walking about. Personally, I like to play him behind the striker," said the coach.
"However, there is no lock on his position. In some games, I like him on the left or the right, but at this point in his career, I see him playing behind the striker," he added in praise of the country's highest goal-scorer.
To tone down the euphoria and give it a realistic touch, the Englishman said winning just one game against Puerto Rico wouldn't change India's FIFA rankings.
"I hate losing. So, whenever we win, it's okay for me. Apart from the result, we got to play. We need to play internationals to climb up the rankings. Winning one game won't help. Beating Puerto Rico, who are above us in the rankings, would help but we need more. That's what I'm trying to do since I came here.
"They are 38 places above us. Anyone above us is good enough. Was this game appropriate for us, absolutely! This gave us an opportunity to play against South American opposition which we do not normally do.
"This is why I wanted us to go to the US in the first place, to get games against sides like Guyana, Puerto Rico, Trinidad and Tobago, these kind of teams, as we learn more playing against them as against smaller nations closer to us," he explained.