Wales forwards coach Robin McBryde fears that prop Gethin Jenkins might have become "a marked man" in Test match rugby.
Jenkins was sin-binned for the second successive RBS 6 Nations game on Sunday when Wales' title hopes were destroyed by England at Twickenham.
As when he received a yellow card in the France Test two weeks earlier, 104 times-capped Jenkins looked bewildered that he had been punished for a perceived scrummaging offence.
And McBryde has now gone into bat for the 33-year-old, while also revealing that Wales will contact Twickenham match official Romain Poite and International Rugby Board referees' chief Joel Jutge for "clarity" over the scrums.
"My concern is that Gethin is a marked man and that there is a preconception out there with him," McBryde said.
"He is vastly-experienced and been there with the (British and Irish) Lions and Wales.
"We feel we have a dominant scrum, and if you come up against one you will try every ploy in the book to negate the advantage the opposition have.
"We only had two scrums on our ball. We got a penalty from the first - clearly dominant - and the second we cleared our lines off a solid foundation. My concern is that we are falling foul because of a perception out there.
"Things we focused on going into the game, with good dialogue from Joel Jutge, were stability when the packs come together and not pushing through the mark. We did that to the best of our ability, and it takes two sides to agree to that.
"It is very hard for a loosehead to create an angle for himself when the guy you are pushing against is not pushing straight. I felt Gethin was pushing straight.
"I am not saying we did not quite get it right on a couple of occasions, but there were others when I felt we had to be given it as we were going forward.
"It is tough on the referee because I think there was a poor call from one of his touch judges with regards to Gethin again, when clearly the (England) tighthead was binding his arm and he (Jenkins) could not get his arm up.
"Romain can't see that, and I am not being too critical of him. We have to get that clarity so we can move on.
"Until then, it is a guessing game, and the fact there was only one reset (scrum) and decisions were made straight away, he has to be pretty certain he is making the right decision and not guessing."
England ran out comfortable winners on Sunday, scoring tries through scrum-half Danny Care and centre Luther Burrell and leaving Wales with plenty to ponder before hosting Scotland in their Six Nations finale next Saturday.
"I am not concerned with the scrum. I am concerned that we have obviously fallen the wrong side of Romain Poite," McBryde added.
"As far as I see it, it was a hugely-competitive area of the game. We were quite dominant on a couple of scrums, and I felt we should have benefited from the decision.
"The unfortunate thing is that one man has been singled out, and everyone could see the dejection on Gethin's face when he came off as to regards he didn't know what else he could have done.
"I will be sending an email to both Romain and Joel for clarity, because it is important in how we move forward, learn the lessons and let's make sure we are looking at the same things that Joel is looking at."
While England, Ireland and outsiders France will go for silverware during the tournament's final weekend, Wales can only reflect on a disappointing campaign.
Wales boss Warren Gatland will name his team on Thursday, with full-back Leigh Halfpenny sidelined due to a dislocated shoulder, but scrum-half Rhys Webb (ankle) and lock Luke Charteris (neck) have not been ruled out of selection plans at this stage.
"We know where we've fallen down. We know where we weren't good enough," McBryde said.
"There was a big expectancy asked of us again against England. We didn't live up to it against Ireland (Wales lost 26-3), and we haven't lived up to it against England.
"That expectancy surely will have grown for our last home match against Scotland, and we can't shy away from it. We have got to answer a few questions, and you can only do that on the field."