India's hockey coach Roelant Oltmans said Tuesday that skipper Sardar Singh had been replaced as captain for the Olympics as he backed the sport's one-time giant to continue its recent revival in Rio. After unveiling the 16-strong men and women's squads which will travel to Brazil, Oltmans said that goalkeeper Sreejesh Ravindran would lead the men's team under a new "rotational captaincy" program. Singh, who has been captain of the team for the last four years, was picked in the squad and Oltmans insisted he remained a key player. But the move comes after he was accused in February of sexually harassing a woman who claims to have been his former girlfriend, accusations that Singh has strenuously denied. "I have been here for a three and a half years now and what I observed is a fairly hierarchic structure and when there is only one captain for long then the players shy away from responsibility," said Oltmans. "In a team, during a game, I need players who take responsibility. Changing the captaincy on the pitch gives far more responsibility. "Sardar is an important player but I am sure this (rotational captaincy) will help the team and it will help him as well," he added at a press conference in New Delhi. India once dominated the men's game at the Olympics and has won a total of eight golds. However the last of these was in Moscow back in 1980 and it finished last at the London games four years ago. Although not one of the favorites at next month's Olympics in Brazil, there have been encouraging signs for India of late and it was runners-up in the recent Champions Trophy. "You have seen in the last couple of years that we are getting better and better," said the 62-year-old Dutchman. "If that's enough already to get medals at the Olympics that's something we have to prove. India's strong showing at last month's Champions Trophy in London has seen it rise a couple of spots to fifth in the world rankings, still some way behind Australia at the top of the chart. "It's clear from where we are, winning a couple of medals in FIH (International Hockey Federation) tournaments, look at the world rankings at the moment," said Oltmans. "It is all signals of revival but nothing more than that. It is up to us to prove it during the Olympics that we are there for a longer time," added the coach, who is also the team's high performance director. The Indian men's team has been drawn in Group B alongside Argentina, Canada, Germany, Ireland and Netherlands. The women's team, which is making its first appearance at an Olympics for 36 years, has been grouped with Argentina, Australia, Great Britain, Japan and the United States.