Edinburgh, on the other hand, will be looking to retain their top four spot, they have been in the play-off zone since the second week of the season.
Elsewhere on Friday, in another Scottish v Irish battle, Glasgow Warriors host Connacht at Firhill Arena.
The westerners have fared well in the Amlin Challenge Cup over the last couple of weeks, but not so well against Scottish opposition having lost their last four matches against opponents from that country.
In the first of the weekend's Welsh derbies, the Scarlets welcome the Newport Gwent Dragons to Llanelli.
The Scarlets have performed well in the Heineken Cup, leading their pool with two wins out of two, and will be looking to bring that success to their Magners League games.
Having led the league table after the first round, the Dragons currently sit just outside the play-off zone.
On Saturday, current Magners League leaders Leinster are also on the road, they face fellow Irish province Ulster, who temporarily found themselves at the summit following their bonus point 45-24 victory over Scarlets in the last round.
The reigning European champions, however, have a good record at Ravenhill - having lost just one of their past seven games at the Belfast ground.
The Ospreys are well-placed sitting third in the table, but with five points separating the top seven teams, any slip-up will let one of the chasing pack into a coveted top four spot.
MAGNERS LEAGUE - ROUND 6 FIXTURES:
Friday, October 23 -
Scarlets v Newport Gwent Dragons, Parc y Scarlets, 7.05pm (live BBC Wales/deferred coverage Setanta Sports Ireland)
Glasgow Warriors v CONNACHT, Firhill Arena, 7.30pm
Edinburgh v MUNSTER, Murrayfield, 8pm (live Setanta Sports Ireland)
Saturday, October 24 -
ULSTER v LEINSTER, Ravenhill, 6pm (live Setanta Sports 1)
Cardiff Blues v Ospreys, Cardiff City Stadium, 6.30pm (live S4C/deferred coverage Setanta Sports 1)