Leinster and Ireland scrum-half Jamison Gibson-Park remains a doubt for Saturday's BKT United Rugby Championship clash with Munster as he continues recovery from a groin injury.

The 34-year-old has not featured in any of the province's first four games of the season, including their Champions Cup opener at the weekend.

Assistant coach Tyler Bleyendaal explained that although their star man is back in light training, it is still very much a wait and see situation if he features at the weekend.

"Jamison is not training fully, but he is back," the former out-half explained on Monday.

"He was back involved today and he did a little bit last week as well, (but) he's really just seeing how he feels at the end of the week, before we make a decision.

"He was out there today running around, which is a positive sign I think, but it's one of those ones where it has to be assessed probably a bit closer to the time."

Leinster are already without captain Caelan Doris, internationals RG Snyman, Jack Boyle and Paddy McCarthy, while Lions number eight Jack Conan is ruled out of the first interprovincial derby of the season after picking up a shoulder injury in the win over Clermont.

All of this comes ahead of Andy Farrell naming his squad for November's Nations Championship matches later this week.

Leinster could be calling upon the fit again Jordan Larmour however, as he returns from a calf problem that also kept him out of the opening block of games.

Bleyendaal admitted that the agile winger would be a welcome returnee when he makes his season debut.

"I think Jordan is a massive threat on the attacking side of the ball and we're just so grateful to get him back on the pitch," he said.

"He's had a tough run of it and we look to integrate him and hopefully get him available as soon as possible because get the feet dancing and he can really challenge the opposition."

Leinster and Munster will lock horns this coming Saturday in the second interprovincial fixture of the season, and Leinster's first. It comes just over a year on from the southern province’s shock 31-14 win in Croke Park, and Bleyendaal says he has been impressed with their early season performances.

"Yeah, I think they've been really impressive," the New Zealander said.

"(They've been) really abrasive, strong in the contact area, a good mix of youth.

"They've probably had their hand forced in a few positions, but you can see it's a pretty exciting group and they seem to be playing with a lot of confidence at the moment.

"Some really good results from Munster and that's why it's going to be a massive challenge for us where, you know, we're going to have a good week's preparation, but we're going to have to make sure we front up physically and mentally come the weekend."

Despite an ever-increasing crossover of talent, the rivalry remains as brutal as ever.

That same spite and emotion was on display at the weekend from the men in red, as they produced a fine performance in memory of the late Anthony Foley.

Bleyendaal featured that season for Munster, and is wary of the threat they can bring when fired up.

"I think when a team has that raw emotion and plays with that emotional kind of spike and connection that it just brings everyone together," he said.

"It's a very powerful thing and I think with Munster, as you saw on the weekend, they had the bit between their teeth about playing for a bigger cause.

"I think if that emotion is still there for them, it's going to be a really big challenge for us. We have to make sure we're not just matching it, we have to try and lead with that emotion as well and the physicality that it often brings."