The teams sit in fourth and third places respectively, with just two points separating them in the table, so each will be looking for a victory to consolidate their place in the play-off zone.
On Saturday there will be a continuance of the Ireland v Wales rivalry that will be on show earlier in the day at the Aviva Stadium, only this time at provincial and regional level when Munster welcome Cardiff Blues to Thomond Park.
Munster have retained their top of the table position since round 6 and are unbeaten at home this season, so the Blues will have a hard task on their hands if they are to take the points from this game.
Also on Saturday the Scarlets travel to Italy to face Benetton Treviso, a game the Welsh region really must win if they are to push for a place in the end of season play-offs.
The remaining three games are all on Sunday, starting with the Newport Gwent Dragons' early kick-off at Rodney Parade. Visitors Edinburgh have not won at the venue for over seven years, a record they will no doubt want to overturn.
Glasgow Warriors, who are placed just outside the play-off zone but have two games in hand, must hope that the weather does not have an adverse effect on their game against Connacht, as their two previous PRO12 home matches were both rained off.
The final game of the round, Leinster away at Zebre, does not kick off until 6pm local time (5pm Irish time) to avoid a clash with the France v Italy Six Nations game.
Last season's league champions Leinster have not dropped below fifth in the table all season, and good performances over the international period could stand them in good stead when it comes to defending their title.
RABODIRECT PRO12 - ROUND 13 FIXTURES:
Friday, February 7 -
ULSTER (4th) v Ospreys (3rd), Ravenhill, 7.35pm (live BBC 2 Northern Ireland)
Saturday, February 8 -
Benetton Treviso (10th) v Scarlets (7th), Stadio di Monigo, 2pm (live Sport Mediaset)
MUNSTER (1st) v Cardiff Blues (9th), Thomond Park, 7.15pm (live TG4/S4C)
Sunday, February 9 -
Newport Gwent Dragons (6th) v Edinburgh (8th), Rodney Parade, 1.05pm (live S4C/BBC ALBA)
Glasgow Warriors (5th) v CONNACHT (12th), Scotstoun Stadium, 2pm
Zebre (11th) v LEINSTER (2nd), Stadio XXV Aprile, 6pm local time/5pm Irish time (live Sport Mediaset/www.RTE.ie stream)