Jason Holder says West Indies are acutely aware of their one-day issues as the countdown to the World Cup gathers pace.
Fielding was the one area that the West Indies captain emphasised was a concern ahead of travelling to the UK in early May.
Holder was speaking after a plan to select the 50-over players for unity's sake appeared to backfire in a 3-0 Twenty20 series humiliation against England.
"We just didn't play the surfaces as well as we would have liked. But I am not too disheartened by the performances," he said.
"We obviously kept our ODI squad together to play T20, just to keep the competition guys together for a bit longer. We have our plans pretty much nailed down for the ODIs and we played a really good ODI series.
"Yes, there's still a lot of improvement to be had and fielding is obviously one of our key points to freshen up on before we go to England."
West Indies prepare for their World Cup campaign with a tri-series in Ireland starting on 5th May.
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