Skipper Shay Given admitted the Republic of Ireland were their own worst enemies after conceding goals at the start of each half in the 3-2 friendly defeat at home to Poland.
Mariusz Lewandowski put the visitors ahead in the third minute and Roger Guerreiro doubled the advantage two minutes after the interval.
Stephen Hunt pulled one back with an 88th-minute penalty but Robert Lewandowski immediately added Poland's third and Keith Andrews' strike in injury time set up a frantic finish.
"It was a hectic finale to the game but I think we gave away disappointing goals," said Given. "We had the worst possible start to both halves, being 1-0 down after a couple of minutes is not the best.
"We really dug deep but we are obviously disappointed. After they scored early in the game I thought we were the better team in the first half.
"They got lucky breaks for the second and third goals but they are a good side and they took their chances well. We're disappointed we didn't get a goal right at the end, Kevin Kilbane had one cleared off the line."