Using his aggression as a force for good may be behind Harlequins prop Joe Marler’s current form, but he fears he is one mistake away from another enforced spell on the sidelines, writes Stuart Amos.

The 21-year-old put in a man-of-the-match showing – closely followed by skipper Chris Robshaw – and had a try disallowed in last week’s 25-17 Heineken Cup win over Connacht.

Marler picked up a three-week ban for striking an opponent in the Premiership opener against London Irish at Twickenham, but has been in storming form since his return to action in October.

And the former Richmond upon Thames College student, who is pushing his case for a full England call-up, admitted his discipline remains a work in progress.

“It would be easy to say I have learned from my mistake,” he said.

“Ideally you’d like to say it won’t happen again, but it is a learning process and that process could take quite a long time.

“What I would say is I’m learning to channel the aggressive side of my game in a positive way and it seems to be working at the moment.”

An opportunistic Karl Dickson score and 20 points from the boot of star fly half Nick Evans secured the spoils on Friday as Quins eventually held off a combative Connacht.

Former Quins full back Gavin Duffy had set nerves jangling with a second-half try as director of rugby Conor O’Shea’s men nearly let slip a 19-10 advantage.

And Marler, who refused to take the plaudits for the win, reckoned his contribution paled in comparison to the efforts of the squad.

“A man-of-the-match award is just a bit of a gimmick really. The biggest thing was actually getting the win because the boys had to really dig in against tough oppostion,” he added.

“Nick Evans is a massively calming influence because it gives the boys confidence to know he is going to deliver.

“My job is to scrummage and to provde the ball for the likes of Nick. That is what I’m paid to do. I enjoy tackling and carrying the ball, but I have to do my job first.”

Quins, who have won all 11 of their games so far, go to Gloucester on Saturday in the form of their lives.

But Marler admitted it will be difficult to hold on to their unbeaten record, “The Heineken Cup is where we want to be,” added Marler.

“Gloucester haven’t quite made a name for themselves in Europe. These games are so intense and this is another tough test.”