Republic of Ireland defender Sean St Ledger was disappointed by his side's defending during their 3-1 defeat to Croatia.
The 27-year-old cancelled out Mario Mandzukic's opener midway through the first half, but Nikica Jelavic put Croatia back ahead following a miskick from Stephen Ward.
A Shay Given own goal ended the contest after the break and consigned Ireland to defeat in their Euro 2012 opener.
"We conceded sloppy goals which is unlike us, we are usually pretty tight," said St Ledger. "The second one was dubious, it could have been offside and we thought it was a foul.
"We had to come out in the second half and the next goal was important. Obviously they got it and when you are 3-1 down to a side like Croatia it's always going to be tough.
"It was unlike us the goals we conceded. I wouldn't say Croatia split us open but they were poor goals to concede."
Birmingham-born St Ledger has now made 29 senior international appearances, scoring three goals.