Appleyard joined the Ospreys over the summer

The 33-year-old signed a three-year deal in February and joined over the summer, but the Ospreys claim there is an option for them to part company.

"It's a massive shock, I felt I'd made great gains with individuals and the structure of the defence, I'm very disappointed," said Appleyard.

The Ospreys say the decision is based on business and operational factors.

"We have benefited from the passion, commitment and work ethic that Rob has brought to the role," said regional rugby manager Derwyn Jones.

"We wish him all the best for his future in coaching."

It is believed that the matter of Appleyard's contract situation is now in the hands of solicitors.

The former Swansea, Cardiff and Sale flanker, who has nine caps to his name, was absent when the Ospreys lost 23-7 at Gloucester on Saturday.

It was their third defeat in a row and the fourth of a hugely disappointing early season.