"It does worry me," Mani told reporters in this western Indian resort city ahead of the third One-day match between India and England.
"The Future Tour Programme of the ICC, which has been rescheduled from an earlier five years to six years, will not put pressure on the players. It will start from next year," Mani said on Sunday.
Under the programme, every Test-playing nation will have to play each other away and home once in six years instead of the present five.
Each country, under the ICC rules, will have to play only two Test matches and three One-day internationals with no compulsion to play the shorter Twenty20 version of the game.
"There should be a clear rest period for players. The cricket boards must manage cricket and players but they do manage to fill in with some match or the other," Mani said.
The board "sometimes push in an additional 10 matches an year after reaching an agreement with their players," he added.
Mani, who is in India to settle an ongoing row over the Champions Trophy, said the event will start on October 7 leading to the finals on November 5.
"We have some outstanding issues with the Board for Control of Cricket in India (BCCI) and those will be resolved within a week," he said.
"One issue is the amount of tickets to be issued to the ICC sponsors and the other is whether there is a need for a fourth venue. If there is a fourth venue who will pay for it? Now BCCI has said it will pay," Mani said.
The top six teams in the ICC rankings will not have to play qualifiers.
Sri Lanka, the West Indies, Zimbabwe and Bangladesh will have to qualify, Mani said.
Australia, England and India belong to the first group while South Africa, Pakistan and New Zealand form the second.
Mani said the ICC plans to hold a womens' world cup in 2009 and a 20:20 game involving all Test-playing nations in the same year.