The 32-year-old left the Sharks on Monday after agreeing to terminate his contract early.

Diamond told BBC North West Tonight: "We had a difference of opinion really, me and my coaching staff think we are on the right trajectory and doing things right.

"We had a disagreement about various things."

He added: "We didn't want to fall out over it but the best thing is to part company.

"It is a bit of a shame but these things happen. We have to put it bed quickly and move on."

Diamond is confident that his side, who are second in the Premiership, will not be unduly affected by Ashton's departure.

"We've got Marland Yarde, Byron McGuigan, Denny Solomona, Arron Reed, Tom Roebuck - plenty of players," he said.

"We've got a squad good enough to cope with one or two people coming and going."

Ashton, the Premiership's third-highest ever try-scorer with 86, has been linked with a move to Harlequins.

Analysis

Harlequins scrum-half Danny Care on BBC Radio 5 Live's Rugby Union Weekly Podcast

I saw the news and got on the phone to see how he was. You see that and think something big has happened.

He is going to come on the podcast and tell everyone about it next week. He is currently looking for a club.

He is fine. It is not a wage-cap issue, it is not a misdemeanour issue, just him and the club have decided to part ways and he is now on the market. I'm pretty sure a lot of clubs will be after him.

I may have stoked the fires a little bit with the picture [below]. It's ruffled a few feathers. People enjoy a bit of a transfer saga. It's big news.

He hasn't gone in there and demanded to leave. This isn't him pushing a move to somewhere else. He is genuinely now without a club. The one thing about him, he can't sit still. He wants to play and do the thing he is best at so he very much wants to get back to somewhere very soon and play some rugby.