They have won the last five on the trot and return to the Principality for the second time in a week after last Sunday's 25-11 win over Ospreys at the Liberty Stadium.
Munster are going for a clean sweep of 8 successive wins over Welsh regions this season, a feat that has never been accomplished by any side before.
When the sides met earlier in the season, Munster needed a last-minute try by Ronan O'Mahony to secure a 16-10 win at Musgrave Park.
British and Irish Lion Jonathan Davies and 23-cap England international Olly Barkley start in the centre for a strong Scarlets side tomorrow night and Munster Head Coach Penney is well aware of the Scarlets' strengths:
"Olly [Barkley] brings a wealth of experience to their inside backs combination, he's a very talented player but they're a good side there's no doubt about that and they'll be difficult over there.
"They [the Scarlets forwards] are lively and they're very aggressive, it's something that we need to be really cognisant of and try to combat that because it's a big part of their game and they have destroyed a few packs," he added.
Sixth-placed Scarlets kept their play-off hopes alive with a 25-21 win over Edinburgh in Wales last weekend. The Simon Easterby-coached outfit beat Treviso in their previous fixture but have not won three in a row in the tournament since last April.
The Welshmen have, however, won three of their last four fixtures with Irish provinces at Parc y Scarlets. Scarlets' 18-10 victory over Munster at home in February 2013 ended an impressive run of success for the away side in matches played in Llanelli - Scarlets not having beaten Munster on their own park since March 2007.
Despite beating Edinburgh last week, Scarlets Head Coach Easterby is looking for a much-improved performance from his side.
He said: "Munster are a pretty good outfit at the minute and are pretty settled. They are still able to pick a very strong team despite missing a number of internationals.
"We are under no illusion that they'll be coming here nothing less than well equipped to mix up their game and we will have to be at our best and far better defensively.
"Having narrowly missed out on a victory late on in injury time against Munster at Musgrave Park before Christmas we've had plenty of motivation in training this week! We put ourselves in a really good position to win away from home but gave them a foothold in the dying minutes and managed to stick at it."
Munster face Scarlets at Parc y Scarlets tomorrow evening at 6:30pm. The game will be televised live on RTE and S4C with live updates here.
Munster are back in action at Thomond Park next month with more details here.