Leinster's Tadhg Furlong, Robbie Henshaw, Hugo Keenan and Josh van der Flier are all in the running for the EPCR European Player of the Year award.
The 15-player long list of nominees was released on Wednesday, with the quartet included.
Toulouse also have four nominees: Jerome Kaino, Julien Marchand, Romain Ntamack and the talismanic Antoine Dupont.
Ronan O'Gara's La Rochelle, who will face Leinster in the Heineken Champions Cup semi-final on 2 May, have five players included: Gregory Alldritt, Levani Botia, Kevin Gourdon, Raymond Rhule and Will Skelton.
Matthieu Jalibert of Bordeaux-Begles and Clermont Auvergne’s Kotaro Matsushima complete the list.
The list will be reduced to five players in early May, following the Heineken Champions Cup and Challenge Cup semis. It will be decided by a combination of the public vote and the verdict of the judges. Players not included in the initial list of 15, but who make a significant impact in one of the semi-finals, could also be considered for the shortlist.
The voting will then re-open and the winner will be announced following the Heineken Champions Cup final on Saturday, 22 May. Fans can cast their vote here.
Rob Kearney is the last Irishman to win the prestigious award, collecting the prize in 2012 having helped Leinster to win the Heineken Cup.
EPCR European Player of the Year 2021 award nominees
Gregory Alldritt (La Rochelle)
Levani Botia (La Rochelle)
Antoine Dupont (Toulouse)
Tadhg Furlong (Leinster)
Kevin Gourdon (La Rochelle)
Robbie Henshaw (Leinster)
Matthieu Jalibert (Bordeaux-Begles)
Jerome Kaino (Toulouse)
Hugo Keenan (Leinster)
Julien Marchand (Toulouse)
Kotaro Matsushima (ASM Clermont Auvergne)
Romain Ntamack (Toulouse)
Raymond Rhule (La Rochelle)
Will Skelton (La Rochelle)
Josh van Der Flier (Leinster)