Ireland captain William Porterfield has told his players to "leave everything on the pitch" against South Africa on Tuesday.

After the elation of their victory over England, defeat to the West Indies in their fourth World Cup match meant Ireland's prospects of qualification to the last eight took a sharp nosedive.

To maintain any hope of a slot in the knockout phase the Irish must defeat the might of the Proteas and then overturn fellow associates Holland.

Yet Porterfield's side have been widely praised for their professionalism and competitive spirit in the tournament and the opener insists his side can push South Africa all the way at Eden Gardens, Kolkata.

As well as England, Ireland also took the scalp of Pakistan at the last World Cup and that remains an inspiration.

"The West Indies was a massive game for us, no doubt about that," said Porterfield.

"If we had picked up two points it would have put us in a great position.

"But four years ago, no one gave us a chance when we were going out against Pakistan. We're obviously going to play South Africa, who are one of the favourites, but we've been playing some good cricket, so there's no reason we can't go out there and win two games and leave everything on the pitch.

"We have to play with freedom and come hard at them."

Porterfield has found himself at the centre of a mild controversy after he publicly questioned Asoka de Silva's decision to give Gary Wilson out lbw against the Windies.

Ireland referred the decision and a replay showed Wilson was struck outside the line of off stump as well as appearing to play a shot.

De Silva apparently took the opposite view and upheld the dismissal.

Asked again about the decision, Porterfield told www.irishcricket.org: "The word we got was that the on-field umpire went up to see if he hit the ball before it impacted the pad. Surely if you're asking if it was pad first or bat first then you know he's playing a shot.

"In my opinion they got it wrong and maybe they'll come out and say they got it wrong, I don't know."