17 Leinster players were capped for Ireland during their title-winning charge, while team captain Paul O'Connell, Conor Murray, Peter O'Mahony and Tommy O'Donnell were Munster's only representatives.
In previewing the top of the table clash at the Aviva Stadium, Penney made reference to Leinster's lion's share of Irish squad places.
"Leinster have a group there who have been conditioned to Test matches. We have a group that have played no rugby basically for three weeks," he suggested.
"The odds are stacked and you would expect the team that has had the ability to be conditioned to Test match rugby to be fresh and excited about the opportunity to put the blue jersey on at home.
"So it will be challenging. There is no doubt about it. It is basically Munster playing the Six Nations champions. That is the reality of the situation."
But, at the same time, the New Zealander warned: "If we go out there to try to win individual battles (in an Ireland context) we will get spanked. I reckon that's a really dangerous path to go down.
"The game will be a massive occasion and we just have to make sure we are disciplined and that we are playing for each other.
"We have to put all the individual battles to one side because that is going to be a distraction we don't need."
Leinster forwards coach Jono Gibbes accused Penney of 'stirring it a little bit' at yesterday's Leinster press briefing. "I really don't know if I really believe all that stuff to be honest," he said.
Rob Kearney also admitted that if the shoe was on the other foot the Leinster players would use the disappointment of missing out on international places as a motivating factor.
"I think you probably would. It is in the nature of being a competitor," said the Ireland full-back.
"I think if you don't use something like that to fire you up and use it to your advantage, there is something a little bit wrong with you. I have no doubt they will use that.
"There's no doubt that we've things to prove as well, that there was such a strong Leinster contingent there (in the Ireland squad). We have to show why. So it is a double-edged sword."
Gibbes is expecting another intense encounter on Saturday night, with Munster coming to the capital in 'pretty confident' mood.
"Look at what they have done this year. They have got a home quarter-final, they've only lost three games, they're off the top of the league by two points - I don't know if they need all the peripheral stuff talked about by us," he added.
Meanwhile, Munster hooker Damien Varley has played down the relevance of the Six Nations to Saturday's derby - insisting the province's full focus is on winning in Dublin and getting the league points that would put them top again.
Asked if the Munster players' lack of recent opportunities with Ireland would have any bearing on the Dublin duel, Varley insisted: "I see it as a top of the table clash and we are number two in the table as it currently stands.
"The Six Nations is a different tournament and a different element completely. We're focused solely on the fact that this is probably the biggest derby game of the season.
"It's an excellent opportunity for us to hone in on what we need to prepare for the following week (against Toulouse in the Heineken Cup). That's all the squad is focused on."
Munster come into the round 18 fixture on the back of a forgettable 14-3 home win over Benetton Treviso, with Keith Earls and James Downey scoring their only tries.
Varley, the captain for the night, knows a repeat performance will not be good enough against a side that leapfrogged them in the RaboDirect PRO12 standings at the start of the month.
"We made some silly unforced errors (against Treviso) and I think going into the next two weeks, we have to be more clinical in everything we're doing - particularly in attack and probably bring a bit more intensity.
"The games lend themselves to that in the next two weeks anyway but (we have to be) very clinical in our decision-making and our handling skills."
Varley was making his first appearance since January after a spell on the sidelines with delayed concussion and plantar fascitis, and was pleased that Munster's scrum was 'one of the many positives' against the Italians.
"I think our attack at times was very, very good, albeit sometimes we made some unforced errors which was disappointing," he said.
"Our defence I thought was good and our discipline was really good compared to penalty counts in previous games."
The Munster squad attended an overnight camp at the Mardyke in UCC last night and are training today ahead of Saturday night's showdown with Leinster.
On the injury front, prop John Ryan had to be replaced early on in the Treviso game with concussion. The Corkman is ruled out until he completes the IRB return-to-play protocols.
Donnacha Ryan underwent a scan yesterday and will visit a specialist later today after hurting his right foot on Saturday night.
There was good news for Niall Scannell as the hooker returned to play 80 minutes for Dolphin against St. Mary's College last Saturday after suffering a hyper-extension of his elbow at training in January.