Suresh Raina has said the combination of two new balls and only four deep fielders was putting tremendous pressure on bowlers in ODIs, but added there was no choice for them but to adjust and learn to cope.

"I think it's tough for the bowlers," Raina said in Ranchi ahead of the fourth ODI against Australia. "We have to admit that. When five fielders are inside (the circle), and if a regular bowler can't keep it tight, it will be very difficult for a part-timer. There's pressure on bowlers on what line and length to bowl. They have to be very sure of what their plans are and how they have to bowl to each batsman.

"You can bowl two bouncers, but there are four other deliveries to bowl also. The ball doesn't reverse much because it's quite new. The ball is only 25 overs old at the most. Even spinners don't get that much turn. But whatever it is, we have to adjust to how things are. We can't give excuses. We just have to bat well and bowl well. No doubt it's good for batsmen, and we have no complaints. We have to play by the rules that the ICC makes, and as players do our jobs."

Raina also backed the beleaguered Ishant Sharma to rebound strongly, after the fast bowler conceded 30 runs in the 48th over of Australia's chase to lose India the Mohali ODI. Ishant has been the most expensive specialist bowler in the series, going for 7.87 runs an over. "It can happen to any bowler in the last few overs," Raina said. "Ishant has practised well in the last two days. I hope he stays strong in his mind, and if he stays positive, we'll definitely see a good performance from him. He has worked very hard in the last two days. I hope he will come back strongly against Australia tomorrow."

Twice in three games, the home batsmen have been unsettled by Australia's quick bowlers, especially Mitchell Johnson, but Raina denied the visitors had gained any psychological advantage over India. "I wouldn't say we are under pressure. We won the first game (T20) in Rajkot, then they won in Pune, and then we won again in Jaipur and they won after that. It's a good contest. We are both young teams.

"Sometimes our batting clicks, sometimes our bowling does. But whoever does well on the day, whoever has good plans and positivity and can feel good about themselves is important. Everyone talks about so much cricket happening, but it's important to see how you're feeling, how mentally strong and tough you are.

"Johnson bowled well no doubt, and he had luck on his side. There's no doubt the batsmen have to do well in the middle order - Yuvi paa (Yuvraj Singh), (Ravindra) Jadeja and myself. We'll have to take responsibility and bat well."

Raina has made 39 & 17, Yuvraj 7 & 0 and Jadeja 11 & 2 in the series. In Mohali, it was MS Dhoni who revived India from 76 for 4 with his ninth ODI hundred. Dhoni accelerated gradually to play several powerful strokes at the death, and also brought out his trademark helicopter swing, a shot Raina said belonged completely to the India captain.

"That is a Mahi-bhai exclusive. It's very difficult to play that shot. You have to pick the length early. He has played it for many years. When someone is bowling yorkers at 140-145 (kph) and the ball is aimed at the toes, you have to put the entire load on the back and turn the bat. Other players have their own quality shots, but the helicopter shot suits only him, and it won't suit others. He always clears the rope with it because he has that kind of strength. All players try to hit low full tosses to midwicket or over the bowler's head, but you need to practice that shot a lot."