Peter O'Mahony reckons that Saracens are a "complete rugby team" and that nothing less than Munster's best will suffice on Saturday.
The teams meet for the third time in four seasons in the Heineken Champions Cup with the English Premiership side having dumped out the Reds in the knock-out stages in 2017 and last April.
The Thomond Park clash is not exactly do-or-die but, with a home draw with Racing 92 to their name already, Munster know that more dropped points would make progress very difficult.
O'Mahony, who captained the Lions in 2017, believes that Mark McCall's side, currently bottom of the Premiership after being docked 35 points for salary cap breaches, are an awesome prospect.
"They are just a complete rugby team," said the 30-year-old Ireland flanker.
"They’ve a huge amount of internationals in their side, who play a good brand of rugby, put a huge amount of pressure on teams.
"We’ve found it hard to stop their momentum. They are very good at getting momentum and once they have it [keeping it].
"They've certainly been good in periods post half-time. We've conceded a lot of points to them.
"Their set-piece is immaculate; it’s something they pride themselves on, having been lucky enough to work with some of their players.
"There are lots of areas where they are very good and when you combine all of them they are an impressive team and hard to stop.
"Their phase-play is so good and they hold the ball for such long periods so it’s going to take the biggest performance of the year to compete with these fellows."
England out-half Owen Farrell is expected to feature having returned to club duty last week following his World Cup exploits.
Munster counterpart JJ Hanrahan is looking forward to testing himself against the 28-year-old.
"You are talking about pretty much one of the best players in the world," said the Kerry man.
"You always want to challenge yourself against the best, you have to embrace those opportunities.
"I've come across him before when I was at Northampton and underage. He’s a player I have huge respect for and I admire his talents."
Listen to live commentary of Ulster v Harlequins (3.15pm) & Munster v Saracens (5.30pm) on RTÉ Radio 1’s Saturday Sport