Batsman Azhar Ali has stepped down as Pakistan's one-day international captain following their 4-1 series defeat by Australia last month.
Azhar, 31, became ODI skipper after the 2015 World Cup, and led the side to 12 wins and 18 defeats in the format.
He will be replaced by wicketkeeper-batsman Sarfraz Ahmed, 29, who already leads the Twenty20 side.
Pakistan next visit West Indies at the end of March to play two T20 games, three ODIs and three Tests.
They currently sit eighth in the International Cricket Council's ODI team rankings, but are only three points above West Indies - and only the top eight teams on the cut-off date of 30 September 2017 will automatically qualify for the 2019 World Cup.
Though he is set to continue in the side as a batsman, Azhar will be suspended for the first ODI of the West Indies series after he was punished for a slow over-rate in Australia.
Veteran batsman Misbah-ul-Haq, who continues to captain the Test side, will turn 43 soon after the Caribbean tour ends in May.
In December 2015, Azhar offered to resign over the presence at a training camp of pace bowler Mohammad Amir - who has since returned to international cricket after being jailed and banned for five years for his part in a spot-fixing scandal - but the Pakistan Cricket Board rejected his offer to quit.