Sunil has the talent, needs to be mentally strong: Bhutia

"It's a mental thing. It's about how strong you are in mind. He has got the game...But 70 per cent of the game is about mind. He is a confident guy, he has to believe in himself to do well," Bhutia said of his one-time striking partner.

Chhetri will be plying his trade in the club's B team for the next one year, but Bhutia said there is always scope for moving up the ladder.

"Whether you sign for B, C or D team, if you perform well there is no limit for it. I think the great thing is that he has got the opportunity to play. If he does well in B, he can move up to A," Bhutia told 'NDTV'.

The Sikkimese sniper had no doubt that Chhetri's association would inspire the coming generations in the country.

"He is going to make a huge impact. Signing for such a great club is the first step, performing well will be the next," said the former captain.

Bhutia said, besides Chhetri, it's also a great day for Indian football.

"It's absolutely a great day for Sunil and the Indian football. I hope Sunil grabs the opportunity.

"It's a great club and has produced some of the great footballers. Hope he does well. It will benefit the future Indian footballers."

Cristiano Ronaldo, Nani and Luis Figo have been part of Sporting Lisbon. Eleven out of the 23-member squad, who were part of Portugal's Euro 2012 squad, have played for the club.