Cook: A very tough day
England captain Alastair Cook admitted he was frustrated after his side suffered a nine-wicket defeat to India at Edgbaston, the tourists wrapping up the Royal London Series 3-0 with a game to spare.
Ajinkya Rahane (106) hit his maiden ODI century in an opening stand of 183 with Shikhar Dhawan (97no) as India surged past an inadequate 206 all out with 19.3 overs to spare in Cook's fifth successive series defeat.
Cook told Sky Sports 2: "It's been a very tough day. In the Test match series we turned it round and then on a high we've played some bad cricket - I don't quite know why that is, but we have to try to find the reason for that.
"The most frustrating thing is when you don't play anywhere near your potential and that's what we've done and there are no excuses for that."
After the tourists won the toss and chose to bowl first, Cook believes that the decision would not have made a difference and said India were the better team on the day.
He added: "We were going to bat first anyway, it probably got a little bit better but we're not going to use that....India have outskilled us.
"They bowled better than us, they fielded better than us and they certainly batted better than us so unfortunately it's a hard place to be at the moment, but we just need to stay true to ourselves and really back our beliefs and work incredibly hard.
"That's the only way through it. That's what we did in the Test match, people put their hands up and turned it around and that's the bottom line."
Looking ahead to the fifth ODI on Friday and the next few months leading up to the World Cup, Cook said: "It's always tough when you lose three very quickly - especially in the manner we've lost - but you have to look forward to the next six months of one-day cricket and what's exciting is there is a World Cup at the end of it.
"No one is nailing down their places, people aren't performing. People aren't hungry to keep working and try to turn it around then there's no place for them in the dressing room."
India captain Mahendra Singh Dhoni was delighted with his side's victory and praised his players for their progression throughout the series.
He said: "Since the first game that we played, our performance kept getting better and that's very important because that's what should be happening every game. (After) a couple of good performances (we) could become relaxed to some extent, but I think this was the perfect game again.
"We had a bit of help from the fast bowlers initially and they proved that if they bowled in right areas, they were quite patient with their bowling and they made the job slightly easier for the spinners because the wicket got better as the game progressed.
"It was important we got wickets with the new ball because that really puts the pressure on the opposition."
After hearing the news that he had become the most successful India captain in ODI cricket in terms of wins, Dhoni took time to thank those who had helped him along the way.
He added: "Thanks a lot - I think it's all being part of a good team.
"These are a bunch of youngsters and before this also quite a few senior players who guided us really to how we're supposed to play cricket.
"It is difficult to always win games, but it's important to maintain yourselves when you're not, so I'm grateful to all the seniors that I've also played under, but at the same time also the youngsters that have really pickedup."