The last time out in Dublin it was a nail-biting affair with Leinster coming away with a brutal 13-3 win, although Munster were in it until the last few minutes.
The two sides will meet again in a rearranged fixture after the original match was postponed due to COVID-19 protocols, and despite the challenge and the fact that Munster are way out in front in Conference B, the game comes down to more than bragging rights.
Any team who wants to lift the Guinness PRO14 trophy this season knows they need to topple defending champions, Leinster, and although they stumbled against Connacht, they returned with a roar against Ulster two weeks ago, proving that they remain a major title contender.
Van Graan embraced the challenge and said: “We’ve played some pretty good rugby and we’re pretty happy with where we are at.
“Unfortunately, in a season so long, you have to take it week by week. It doesn't help to pat yourself on the back about what you’ve done because we haven’t achieved anything.
“It’s a good start to the season, we are No 1 currently in our group, but that counts for nothing on Saturday.
“There are four or five points up for grabs, and it’s obviously a big game in Irish rugby and one that I’ve personally enjoyed.”
Having done his homework on Leinster, Van Graan expected another testing encounter.
“They play a very pressurised game. Scrum and maul, they’re potent,” Van Graan said.
“Once they get scrum penalties, they get into your half and will either maul you or they’ll play off that six-man (lineout) of theirs where they get into the vacuum, which they do very well with their centres.
“Then they phase-play, and once they get onto a roll it’s very difficult to stop.”
He added: “They’re a proud club with a very good coaching team. It’s one of the clubs in world rugby that I respect. You have to respect quality and standards and that's what they're about.
“That’s why they're currently top of their European pool and have won the PRO14 the last three years.”
The action kicks off on Friday night with a Welsh derby between the Scarlets and Cardiff Blues, who are involved in a tight tussle on the log where the Scarlets boast a two-point lead over them in Conference B.
The two sides last met a fortnight ago, with the Cardiff Blues winning 29-20 at Cardiff City Stadium.
The match will be particularly significant for Cardiff Blues forward Josh Turnbull, who has also represented the Scarlets, as he is in line to become just fifth player to reach 200 appearances in the Guinness PRO14.
Saturday’s action turns first to Italy where Zebre will be chasing their fourth consecutive victory when they host Edinburgh, and on Sunday Ospreys travel to Galway to face the Connacht, where they will be hoping to achieve a third consecutive away victory.
Guinness PRO14 Fixtures
Friday, 22 January
22h00 - Scarlets v Cardiff Blues (Parc y Scarlets, Llanelli)
Saturday, 23 January
15h00 - Zebre v Edinburgh (Stadio Sergio Lanfranchi, Parma)
21h35 - Munster v Leinster (Thomond Park, Limerick)
Sunday, 24 January
17h00 - Connacht v Ospreys (Sportsground, Galway)