"Today showed you have to play well for the full 90 minutes, anything less will not do," Carey told the club website.
"This was a great game in reminding ourselves what we are all about.
"Generally things have gone well in pre-season, but we dug ourselves into a hole and once you do that, it's very hard to reverse the situation.
"Yes, we created enough chances to pull the game back, but I was very disappointed about how we started."