KARACHI (AFP) - India's South African coach Gary Kirsten Tuesday said it was vital to try different combinations to keep players fresh amid a hectic and demanding international calendar. "I am very much in favour of a rotation policy to keep the players fresh and we need to have a pool of around 20 players," said Kirsten ahead of his team's first match in the six-nation Asia Cup against Hong Kong here on Wednesday. India, three times champions, are in Group B with hosts Pakistan and Hong Kong. Titleholders Sri Lanka, Bangladesh and United Arab Emirates are in Group A. India, who won a tri-series tournament in Australia earlier this year, lost to Pakistan in the final of another tri-series tournament in Bangladesh earlier this month, missing key players Sachin Tendulkar, Zaheer Khan and Shanthakumaran Sreesanth through injuries. Kirsten said the injuries to key players emphasised the importance of rotation. "We have got to rest players and we have got to rotate. Test match cricket is tough with bowlers bowling around 25 overs a day in three to four Tests and it is tough. So we need to rotate players," said Kirsten, who played 101 Tests and 185 one-day matches for South Africa. Kirsten, 40, who took over as India coach in March, said a system needs to be created to avoid injuries. "The system needs to create that and it is unfair to ask the player himself to be rested and he is also worried that if his replacement does well then he will lose his place," he said. "So we need a rotation system in which if we rest a bowler, and his replacement does well, he still remains the number one bowler and gets his place back." Kirsten said a lot of planning and thinking goes into modern cricket. "There is always lot of planning, lots of thinking, new ideas and we are playing so much cricket that there is no time out to work on someone's technique so we need to do it on the road," he added. Kirsten said India need to take every team seriously to win the Asia Cup. "We've got to take every opposition seriously and we've got to try and play proper cricket." "We are always looking at new ways of playing the game. Pick up new ideas, new shot making, just trying to improve their game by five to 10 percent and that can make all the difference," he said. Kirsten revealed his batsmen have been trying the switch hit used so effectively by England batsman Kevin Pietersen in the ongoing one-day series against New Zealand. "We were doing this even before this thing (Pietersen) came up. We are trying things all the time and that's the way cricket is going. We are trying to innovate and that's the way it is."