"I respect everything Sir Alex says and I can understand it," said Burley. "I said before the game that Darren Fletcher is a big part of the future of Scotland and he has done terrifically well for Manchester United.
"Unfortunately, I couldn't foresee that it was going to happen.
"If I knew Darren was going to get a knock I certainly would have taken him off but, as I say, he is very much a key player and I didn't want to lose against Croatia.
"My job is to try to take the country to the World Cup finals and we do need some games to try to get the squad ready.
"I need friendlies and you don't get too many.
"We had a get-together in February when virtually every other international team played.
"I spoke to him [Fletcher] after the game and he was really disappointed, as am I, but these things happen.
"You hope things like this don't happen but unfortunately this time it did."