Koscielny, who will play in Saturday's quarter-final in place of the suspended Philippe Mexes, has opened up over the conflict in the squad.
"Things were said in the changing room," said Koscielny. "They were said but that will stay between us.
"There were some things to say and everyone's aware of that. But these things happen.
"Now we have to turn the page. But we were unbeaten in 23 games so I don't see why we should throw all that away.
"We were below par on every level against Sweden. When we got back to the dressing room we knew we hadn't done what we had to do and some things were said.
"Maybe we did ease up a bit subconsciously. We have to work hard over the next three days to put that right."