India are clubbed along side defending champions Germany, European champions Netherlands, Pan-American Games champions Argentina, Ireland and Canada in Pool B in the Rio Olympics.
And Sunil, who vies to be at his best against the mighty Germans, said the Champions Trophy will provide them much-needed knowledge about top teams, including Germany.
"They (Germany) are the best team in the world. It is my priority to do well against them in the Champions Trophy and at the Olympics. Playing them in the Champions Trophy will help us understand their game better ahead of the Olympics. We discussed Germany in our previous team meetings and we are aware of their stregth and weaknesses," said Sunil.
"Last time, we paid more attention to fitness but this time, it is very different. We are paying attention to overall development as a team and the training has a lot to do with discipline and team spirit which I think has helped us on the field and in understanding each other's strengths and weaknesses," he said.
More From This Section
Sunil was named as the vice-captain of the team for last month's Sultan Azlan Shah Cup in Ipoh, Malaysia, where India finished runners-up.
"Vice-captaincy for me is all about making the youngsters in the team understand their role and motivate them to play to their potential."
Hailing from a poor family, Sunil said he is indebted to hockey for what he is today.
"Coming from a poor family in Coorg, hockey has given me everything I need to lead a comfortable life. And when I play, I remember what the game has given me for the sacrifices I have made. I will do everything to bring glory for the country," he said.
"He (Sunil) is an attacker and brings something exceptional to the team. He understands our demands and he keeps questioning what we are doing in a positive way so that he can understand it and translate it to the younger players," said Oltmans.