The playing surface at Lille's Stade Pierre Mauroy cut up during France's draw against Switzerland on Sunday, with players losing their footing.
Bad weather is being blamed, despite a retractable roof at the stadium, and the pitch will be replaced on Friday.
The Republic must beat Italy to have any chance of reaching the last 16.
Martin O'Neill's side drew 1-1 against Sweden in their opening match, before a 3-0 defeat by Belgium left them bottom of the group going into their third and final match.
Neither the Republic not the Italians have been able to train at the stadium in the build-up to Wednesday's fixture.
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Uefa, European football's governing body, says the last-16 and quarter-final games scheduled to be played at the venue on 26 June and 1 July respectively, will still go ahead.
The new pitch is being brought in from the Netherlands.
"The extremely difficult weather conditions in the past few weeks (rain, humidity, lack of sunshine) have caused irreversible damage to the surface at the stadium," said Uefa.
"We saw the pitch didn't look that great but it's going to be the same for the Italians as it is for ourselves so that makes it a level playing field," said  Ireland left-back Stephen Ward.
"Myself and Wes Hoolahan have played in the League of Ireland so we're used to it."
The Republic of Ireland will play their crucial Euro 2016 group match against Italy on Wednesday on a pitch that Uefa says is "irreversibly damaged".