Outgoing Central Coast Mariners coach Graham Arnold has apologised to the club's fans for walking out at such short notice – and has promised to return one day.

While a move to an Asian club had been mooted for some time, and the Mariners had made basic contingencies for his departure, the speed of his appointment at Vegalta Sendai last week was a shock to many.

Graham Arnold: “I was very sad to leave the Mariners and I apologise to the supporters and everyone else for the way I left." Credit:Brendan Esposito

Arnold returned to the Central Coast on Thursday to formally farewell the players and said he didn't want any bad feelings surrounding his departure for the J-League.

“I was very sad to leave the Mariners and I apologise to the supporters and everyone else for the way I left," he said.