Sale director of rugby Steve Diamond revealed his frustration with the officials after his side lost 24-10 at home to Saracens in the European Champions Cup.

For the second week running against Mark McCall's men, the Sharks had three players sin-binned and Diamond felt the directives being handed to referees made life difficult for officials and players.

Rob Webber, Bryn Evans and TJ Ioane were all shown yellow cards during the game and Diamond said: "That's how rugby is going, isn't it?

"There is a red card every game these days or two or three yellows, so I think we probably need new coaches to be able to adapt to the law-makers - not so much the referees because they are told what to do.

"I just don't think we are being given time to implement our coaching techniques.

"These adaptions have been brought in quickly and the coaches and the players have to adapt very quickly.

"I think the referees are left on the spot and they probably don't know what to do half the time."

Solomona spurned a couple of try-scoring opportunities either side of half-time following his controversial cross-code move from Castleford.

Diamond, whose side grabbed a late consolation through Evans, saw the Sharks crash to a sixth straight defeat.

He added: "Denny probably could have got hold one or two of those opportunities, but these things happen and I thought overall he did all right defensively.

"He could have taken the opportunities, but I'm sure he will get many more.

"It was a better performance than last week and we were probably in the game with 15 minutes to go, but the superiority of the bench that Sarries have compared to ours showed."

Saracens equalled Munster's record of 13 straight wins in the European Cup after Owen Farrell and Nathan Earle scored late tries.

McCall shared Diamond's frustrations with the officiating and revealed England prop Mako Vunipola would be assessed after leaving the field with a knee injury in the second half.

"Mako has got a bit of soreness in his knee which will be assessed in the next couple of days," McCall said.

"Anybody would miss Mako Vunipola but we don't know how long he will be out for yet.

"It wasn't the prettiest game, was it? But give Sale a huge amount of credit because they defended superbly well.

"My own view was that we had control of the territory we gained but weren't as good as we could have been when down their end.

"We just needed to stick at it, keep playing the same way, and continuing to control field position. I think we did a decent job."

On the refereeing, McCall added: "Across the board, it was the kind of game you can get frustrated - it seems to change from one week to the next.

"People want to be able to coach and prepare their team with some consistent interpretations. Maybe that's not always the case.

"I think we need referees to use judgement but you're relying on the opinion of the referee on the day. That's potentially a dangerous thing to do."