Munster prop BJ Botha pointed to a growing tendency by some teams to engage in a little sharp practice in search of an unfair advantage at scrum time. He claimed it had cost Munster more than once this season.
Botha said some opposition packs have tricked Munster by pre-empting the referee. As the official recites the "crouch, touch, set" instruction someone in the opposition pack shouts "set" early.
"It's a heated area in there. We'll own up as a front-row to the majority (of penalties), but once or twice it was our back-row who hit too early. Some opposition shout "set" ahead of the referee and then our back-row goes, which results in the early engagement," said Botha.
"All the back-row is concerned with at scrum time is driving into their second-rows. They're coiled and when they hear "set" they just go for it. I've noticed it happening more than ever in the last two weeks.
"Teams are looking to gain an advantage and it has cost us."
This weekend he expects a more straightforward scrum battle. The Saracens pack have been in storming form since the start of the competition and go into this game knowing that a win would leave them in a powerful position.
Munster, three points behind them, simply cannot afford to lose, not with the daunting return challenge the following weekend in Vicarage Road. "This weekend we know that the battle up front is going to be massive and we have to set a platform here," Botha added. "Saracens are a massive side. They are second in the Premiership and are leading our pool.
"We know what we have to do. We need to put up a massive performance, especially in the front five because they (Saracens) have a serious scrum."
Saracens will certainly look to exploit the inexperience of Dave Kilcoyne at loosehead. Botha acknowledges that the young UL Bohs man is still learning his craft, but has no fears about his ability to handle the pressure.
"Dave has come through the Academy and is learning all the time," he said. "For sure his play in the loose has always been very strong. And he is really standing up and showing what he is capable of in the tight as well.
"He's a very confident player and he's come in and done really well in the eight (pack). This game, against a big English pack, will be another test for him."
Munster are, of course, desperate to make up the ground they lost when beaten by Racing Metro in a game they should have won. That result helped Saracens gain control of the pool, something Munster need to wrestle back over the course of the next two weekends.
"We pride ourselves on our home record and we want to put in a big performance. If we do that then the result will look after itself. There's a lot of excitement around the games this weekend and leading on from a good result last weekend we'll look to build on that," Botha added.