Andy Flower, the England team director, has praised Alastair Cook for the way he has handled the dual challenges of proving himself as a one-day batsman and captain in the 3-2 series win against Sri Lanka. The silverware was secured with a tight 16-run win at Old Trafford where Cook also took his personal contribution to 298 runs.

Apart from the volume of runs, which included a career-best 119 at Lord's, the impressive feature was the strike-rate of 96.75. That number was boosted by his 75-ball 95 at Trent Bridge as Cook provided evidence that he is making strides towards evolving into a effective one-day batsman to supplement his record-breaking Test credentials.

Cook had to face some strong criticism both before and during the series but refused to be drawn into any war of words and constantly said performance on the field was the most important factor. The five matches helped Cook build on the positive impression he made as captain last year when he filled in for Andrew Strauss.

"He had some tricky decisions to make throughout the series, and he was under pressure from a number of quarters," Flower said. "I thought he handled that pressure really well, and made some really good decisions out there today.

"He had to be very flexible, and he was. We saw him handle pressure well out in Bangladesh too, which isn't an easy tour. He grew there as a leader, and without doubt this series will have helped him grow too."

Cook showed hints of innovation in his batting, with some dabs and scoops against the spinners, but on the whole relied on the strong shots that have brought him success in Test cricket. A comparison has been made about how Cook needs to perform a similar role to Mahela Jayawardene in the Sri Lanka team and Flower believes he has shown he can do that.

"Graham Gooch has worked very closely with him on his batting for a long time - because obviously one-day cricket is very different to Test cricket," he said. "I think he's adapted well. It might not look as pretty as a Jayawardene, but it's been even more effective in this series. He should feel very proud of his contribution with the bat, and how he's handled some of the pressure he's been under."

However, not all England's batsmen enjoyed such a productive series. Kevin Pietersen's lean time in ODIs since 2008 continued with 85 runs in four innings, while Ian Bell didn't look at home at No. 6 where he made 81 runs at a strike of under 70. In an Evening Standard column during the series Bell admitted it was a role he was uncomfortable with, but Flower hinted it's one he will have to get used to.

"Ian Bell's job, or anyone else's job when they're picked for England, is to perform," Flower said. "Whether they're happy or not is by the by. They are given a job, and they have got to do it. He's had a tough series. He wasn't the only one - not everyone can succeed at the same time."

Flower, though, will hope that Bell's problems in the one-day arena don't impacted his prolific Test form of 2011 when he has averaged over 300. Thoughts now turn to the four-match series against India which starts on July 21 and the one-day success means England remain buoyant.

"It's always important to win, and we're always under pressure to do so when representing England," Flower said. "The bottom line is we did it, we didn't lose the series. It's a good confidence-builder for those guys that they held themselves so well under pressure."