Ireland have been drawn in the same World Cup qualifying group as favourites West Indies in the tournament which will decide who makes the finals in England and Wales next year.
The Netherlands, Papua New Guinea and the winner of next month's World Cricket League Division 2 will be the other Group A opponents for new coach Graham Ford's side, but the format means the top six teams will play each other before the two qualifiers are decided.
The top three from each of the two groups go through to the Super Sixes and, if the top three seeds in Group B also progress, Ireland would then meet hosts Zimbabwe, Scotland and Afghanistan, the final match possibly deciding the last place in the finals.
Ireland, and indeed William Porterfield, Kevin and Niall O'Brien and Ed Joyce, are all bidding to reach their fourth successive World Cup but, with only two places up for grabs, qualification has never been harder, as captain Porterfield confirmed.
He said: "It's going to be a really hard-fought tournament, with nearly all the sides in with a genuine chance of qualification. There are certainly no 'gimmes' in the competition. It's a pity there are only two places up for grabs.
"We've got a good record against the Windies, beating them in the 2015 World Cup, so we'll take confidence from that. The Netherlands have got some big players back in recent times, so they'll be tough, while Papua New Guinea are improving."
Ireland were due to play West Indies at Stormont last September but the game was rained off without a ball bowled, so their meeting at the Harare Sports Club on Saturday, March 10 will be the first since Ireland's four-wicket win in Nelson, New Zealand three years ago, when Paul Stirling was man of the match, top scoring with 92, and Joyce (84) and Niall O'Brien (79) both went big as Ireland chased down 304.
Ireland haven't faced the Netherlands, who will be their first opponents on March 4, in an ODI since 2013 - the last game finished in a tie - but if Ryan ten Doeschate takes his place then they will be dangerous opponents, while Papua New Guinea have beaten Ireland in two of the last four T20 internationals, but this will be the first 50-over contest.
Zimbabwe, on February 27, and Scotland, two days later, will be Ireland's opponents in warm-up games before the squad move to Harare for all four group games and the Super Sixes.
The Ireland squad, currently in Dubai, will also play four games in South Africa next month - only a game against the Dutch has been confirmed, by them, so far - before they make the short hop to Zimbabwe.
Ireland return to action in the Tri-Series today with the first of two games against Scotland, and Joyce and Boyd Rankin, who were both rested for Saturday's second victory over UAE, are expected to return, while Simi Singh and Jacob Mulder are waiting for their first game.
WCQ fixtures: March 4 v Netherlands, March 6 v Papua New Guinea, March 10 v West Indies, March 12 v Qualifier.