The Welsh region are fifth in the league, 14-points adrift of Tony McGahan's pace-setting Munster but with a game in hand.
But as the scramble for the play-offs intensifies, Cardiff head coach Dai Young is adamant only a win over the red army tonight will do if they are to reach the knockout stages.
"We've got six games left and we need to win at least five of those to have any chance of getting in the top four,"
"Two of the six are at home, including this weekend. It doesn't matter who we're playing we have to win. Every game is massive must win game now."
Young will take great comfort from the fact that the home side have triumphed in the last six clashes between the sides. While Munster have not won in the Welsh capital since 2005.
But he is also all too aware of the threat Munster pose after watching his side fall to a 16-9 defeat in December as McGahan's men stormed back after trailing at the interval.
"It doesn't get much tougher than Munster but we have to start well and make sure we get the points," added Young.
"We're at home and have to win. If we don't it puts us under a lot of pressure.
"Munster haven't got their eye on the Heineken Cup this year but there are very few seasons when they don't come away with something.
"It doesn't matter who they play or whether have their internationals back they're always going to be difficult."
Blues centre Casey Laulala is raring to go and has called on his side to reward their fans with a home semi-final.
"It's a very big finish for us, we're in fifth place now so we need to get the win," said the former All Black centre.
"Munster are always tough but we're ready for it, we've been training hard in the last two weeks. This is the business end of the season and we need to front up and play well.
"Last year we had a lot of success but we were always playing away from home so we'd love to get a home play-off, where we can get the support and we can have a strong finish.
"I don't see anyone catching Munster but you just have to be in that top four. It's not so much about who finishes top now but it's exciting.
"We want to make sure we take part of our own business. We've got a game in hand so that helps but we just have to try to win as many games as we can. But a lot of them are on the road so it's going to be tough.
"Munster are a top team but I don't see why we can't beat them."
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland