According to multiple reports, Barkley rejected the move in the middle of a medical, but the midfielder has since dismissed these reports.
When asked about the failed move, Koeman said: “Of course it was a strange last day of the transfer window.
“But I don’t think it was only that for Everton but for most of the Premier League clubs.
“Ross also came to see me last Tuesday and he explained to me why he turned down the chance to go to Chelsea. That is private.
“But finally the decision was by the player. And that was what happened at that time.”