"I'm sorry Darren's gone, he's a close personal friend and was a great player for Wrexham, but he's wanted to be a manager all his life," said Carey.
"The opportunity at Peterborough came his way and he grabbed it with both hands, I really wish him well.
"I think that Darren was disappointed that he didn't get the Wrexham job, but he reacted in the right way - and did so again when I left him on the bench against Swindon.
"That's the quality of the person and his quality as a professional.
"He is coming towards the end of his playing career, but he definitely had a part to play here in the next three or four months.
"He's moved on, though, and we have to focus on the players we have here now."