Caelan Doris says coming up against so many of his Ireland World Cup team-mates will be "a funny one" when Leinster face Munster in Saturday's BKT URC derby (6.30pm).
The back-row was among 18 Leinster players who went to France as part of Andy Farrell’s squad, while there were eight Munster men on the trip.
The panel first assembled in mid-June and only broke up after the quarter-final loss to New Zealand in mid-October.
Leinster moved top of the standings after Saturday’s 54-5 victory over Scarlets, during which Doris and a number of other front-liners returned to action.
"We had three weeks off, which was nice because it’s a bit of a roller coaster of emotions afterwards," the 25-year-old (below) told RTÉ Sport.
"Obviously massive, massive disappointment and a few very low days.
"After maybe a week or so you are looking forward to getting back into a bit of training and seeing lads again and then, as it came around, you’re thinking, ‘I wouldn’t mind another couple of days [off]’ but since we’ve come back in it’s been good fun, being back with everyone and getting stuck in.
"It’s a funny one, having been in camp with the guys for so long and now... last time I saw them was in camp and now we’re seeing them on the pitch in the Aviva.
"So it’s a funny one from that perspective but all friendships and camaraderie will be put aside for the couple of hours and I’m looking forward to getting stuck in."
Leo Cullen’s side have had the upper hand over Munster in recent years, winning two semi-finals and a final between 2019 and 2021.
However, the most recent crunch game, last season's URC semi-final, which Munster won with a late Jack Crowley drop-goal at the Aviva Stadium, has altered the dynamic somewhat.
"They have certainly improved a lot over the last season and a half," said the Mayo man about Munster, who won the tournament outright in head coach Graham Rowntree’s first season.
"They’ve got quality players throughout and they are gelling as a team the last while.
"You can see it’s coming from how they are training at a high intensity, really improving their fitness and believing in their fitness, playing with quick ball and they have threats throughout.
"Defensively, they are very challenging to play against as well with the amount of breakdown threats they have throughout.
"It’s always a massive game when we play them."
Leinster will have prop Ed Byrne available for selection after he recovered from a hamstring issue, while fellow front-rowers Cian Healy and Michael Milne will be further assessed this week as they rehab from shoulder injuries.
Robbie Henshaw, who was troubled by hamstring issues at the World Cup, and Jack Conan both trained fully and will be in contention, assistant coach Andrew Goodman (below) confirmed.
Tommy O'Brien, who injured his ankle against the Dragons in round four is expected back "around Christmas time", added Goodman.
Reflecting on Leinster’s bonus-point win over the Welsh side, described by Cullen as "flat" and "loose" at times, Goodman said: "We got off to a fast start. We looked a bit at that momentum and how we can keep pressure on teams when we do get a start like that.
"The Scarlets came back well and made us tackle, I think it was 115 times in the 20-minute period after we were 19-0 up.
"Our timing was a little bit off, some of our skillset, back-shoulder passes and little things like that. That will come [together] with another week together and building combinations."
Watch highlights of the weekend's action on Against the Head on RTÉ2 and RTÉ Player at 8pm