Ireland's cricketers have been ravaged with illness ahead of their crucial Twenty20 World Cup clash against West Indies this afternoon in Colombo.

No fewer than six of the squad, plus coach Phil Simmons were unable to attend training at Colts Cricket Club in Colombo on Sunday, as the Irish preparations were severely disrupted - bowling coach Craig McDermott conducted the vastly reduced session, which ironically could work in the Irish favour.

Gary Wilson, Boyd Rankin, Paul Stirling, George Dockrell, Alec Cusack and Stuart Thompson were all left reeling with various symptoms, which required medical attention. Thankfully the latest bulletins suggested all would be passed fit for the knock-out contest.

Heavily criticised in the media for their arduous preparations ahead of the seven wicket defeat to Australia on Wednesday, a light work-out could just be what the doctor ordered if Ireland's World Cup odyssey is to continue in the Sri Lankan capital.

In a year where rain has savaged the domestic programme, it was perhaps serendipitious that the weather did Irish hopes of progression a boost as Australia prevailed by 17 runs under Duckworth Lewis to set up a straight shoot-out between Ireland and the West Indians tonight.

Niall O'Brien was typically upbeat of Ireland's chances saying: "It's not ideal preparation but it's a Twenty20, so there will be a lot of adrenalin and hopefully that will overcome any illness in the camp.

"Shane Watson and David Warner weren't the most popular in the Irish camp a few days ago but they played really well on Saturday and give us a bit of pick-me-up before today's game if we needed it but it's now winner takes all and West Indies are going to feel a bit of pressure.

On the challenge posed by the destructive brilliance of Chris Gayle: "Hopefully one of the bowlers gets his scalp early. He's obviously a fine player but he's only human and can make a mistake we just need to take the chance if it comes."

O'Brien was still positive that Ireland could pull off yet another major coup at a global tournament: "The boys are up for it. Hopefully there will be a big crowd and if we can pick it up 15-20 per cent then hopefully that will be enough for a win. I'd love to open the batting but Porty's (William Porterfield) a fighter and he will be hoping for a bouncer first ball and probably put it in the stand for six."

Ireland v West Indies (Live Sky Sports 3pm).