Ulster, Leinster and Munster all return to European battle as the Champions Cup pool stages approach their climax. 

In the penultimate round, Munster travel to Paris to face Racing 92, while Leinster and Ulster host Glasgow Warriors and La Rochelle respectively.

RTÉ Rugby analyst Donal Lenihan runs the rule over a crucial weekend of action.

Ulster v La Rochelle, Kingspan Stadium, Saturday 1pm

"La Rochelle are flying in the French Top 14 at the moment, joint second with Racing. They've put in some outstanding performances in the Champions Cup this year but they've struggled a bit the last few weeks. Ulster of course have struggled throughout the season. I think it's a huge game for them. If you look at the Pro14 in Conference B they're behind Scarlets and Leinster - I don't see them making the semi-finals there, so I think their season will come down to this game.

"It's going to be very difficult for them. They've a great record against French teams at Ravenhill but normally it's on a raucous Friday night with a massive crowd behind them. This game is 1 o'clock on a Saturday so it doesn't even suit from that point of view. All logic suggests La Rochelle should win this one but I give Ulster a fighting chance on the basis that really their heads are on the block, the players need to stand up and give a real positive performance."

Leinster v Glasgow Warriors, RDS, Sunday 1pm

"Leinster are in a brilliant position. Their form has been excellent. Glasgow in comparison, incredibly really, haven't won a game in the pool. They're flying in the Pro14 but their European form has been very poor. There's a suggestion they might even rest a few players.

"Dave Rennie their coach has suggested he won't start Finn Russell and Jonny Gray but even if he does, I think Leinster, their form is such at the moment... and the prize of winning, it means they're certain of a quarter-final slot and almost certainly a home quarter-final slot, so I'd really fancy Leinster in this one."

Racing 92 v Munster, U Arena, Sunday 3.15pm

"It's going to be huge. They have previous with Racing; they've beaten them three times over the past 12 months so logic would suggest Racing are due to win at some stage. They've been playing well, Racing. There's a suggestion that Dan Carter could be back. It's in this brilliant new U Arena - it's supposed to be an unbelievable arena for rugby.

"That might give Racing a slight edge, but Munster, they had their disappointments over Christmas, I really like how their back row have come together over the last two rounds of the Champions Cup. Peter O'Mahony, CJ Stander and Chris Cloete have been outstanding."

Listen to live and exclusive radio commentary of Ulster v La Rochelle (Saturday 1pm) and Racing v Munster (Sunday 3.15pm) on RTÉ Radio 1.