Cardiff, United Kingdom: Wales fear their experienced prop Gethin Jenkins is being targeted by referees after he was sent to the sin-bin for the third time in six Test matches this season for scrummaging offences.

Jenkins, who against England equalled the record of 104 Wales caps, was shown a yellow card at Twickenham by the French referee, Romain Poite, for persistently not scrummaging straight. He was given 10 minutes off in the previous round by Alain Rolland, who also sent him to the sin-bin against South Africa last November.

If the second-half decision by Poite did not change the course of the match, it made a Wales comeback less likely. Their management team has written to both Poite and Joel Jutge, the International Rugby Board’s referees manager, to ask for clarification and an assurance that Jenkins is not being prejudged.

“I felt Gethin was pushing straight,” said the Wales forwards coach, Robin McBryde. “I am not saying we did not get it quite right on a couple of occasions but it is very hard for a loosehead to get an angle when the guy he is up against is not going straight. There was one poor call from the touchjudge when their tighthead’s binding meant Gethin could not get his arm up and there were times I felt we should have had penalties because we were going forward.

“There was only one reset in the game and a referee must be sure he is making the right decision, not guessing. My concern is that Gethin is a marked man and that there is a preconception with him. We feel we have a dominant scrum and, if you come up against one, you will try every ploy in the book to negate that advantage.”

Poite is known for his insistence on props staying square and not twisting in. He sent the Australia prop Ben Alexander to the sin-bin in the third Test against the Lions last year after 24 minutes for persistent scrum infringements and he gave the Italy prop Martin Castrogiovanni 10 minutes off against Wales last year. He showed Jenkins a yellow two years ago during the victory over Scotland but that was for a breakdown transgression.

“We had good dialogue with Joel before the England game and the things mentioned were stability when the packs came together and not pushing through the mark,” said McBryde. “We’ve got to be careful. Certain players are highlighted, their names have been bandied about with regards to what referees should be looking at. I don’t agree with that because each scrum is different.”

The defeat by England ended Wales’ ambition of a third successive Six Nations title and they need to beat Scotland in Cardiff on Sunday to preserve their record since 2010 of finishing with more victories than defeats. “We are in a hard place after losing a game of that magnitude,” said the centre Jamie Roberts. “We were devastated after the game and we are fortunate to have an immediate chance to put it right. We know we were not good enough on Sunday and we have to look in the mirror.”

Wales were criticised for kicking too much and not addling England’s defence with doubt but Roberts said it was not the game plan that cost Wales but its execution, adding that the players accepted full responsibility for a second heavy away defeat this championship after the 26-3 reverse in Dublin.

“We had opportunities against England but we did not take them,” he said. “We did not play as we trained and that was annoying. We caused their defence problems but we did not take the right options and I was to blame on several occasions.

“We have a very experienced coaching team who have been around a long time. People will say it’s quite predictable but it definitely isn’t. We like to be unpredictable on the field but you have to take the right decisions. A lot of thought goes into our approach and the planning is huge. Running the ball back from deep is a matter of risk and reward: you do not want to play Sevens in your own 22 against a defence as good as England’s. The two tries they scored were off the back of our mistakes.

“We work in an honest environment here and ultimately the players have to take the blame and responsibility for what happened. A number of us have been around for a while and it’s not about the coaches pointing fingers any more but the players putting up our hands, admitting we were poor and searching deep within ourselves to produce a performance against Scotland.”

Wales have delayed announcing their team by 48 hours until Thursday. Full-back Leigh Halfpenny will not play again this season after dislocating his right shoulder but scrum-half Rhys Webb (ankle) and second-row Luke Charteris (neck) face fitness tests with the management considering making voluntary changes with next year’s World Cup in mind.

— Guardian News & Media Ltd