Double blow for Racing Metro 92

Both players were missing for the Top 14 leaders as they narrowly lost to Heineken Cup Champions Toulouse at the weekend and have been ruled out of at least the opening round of European action.

With Argentina playmaker Hernandez sidelined, the French side will be hoping Jonathan Wisniewski recovers from a knock which saw him forced from the field in the second half against Toulouse in time to take the No10 jersey in Dublin.

Having only returned to the French top flight last season, Racing Metro were hoping to rely on the experience on Hernandez in their first outing in Europe's premier competition.

Hernandez has 26 Heineken Cup appearances to his name from his time at Stade Francais Paris and will be desperate to return for the all-French tie against domestic Champions ASM Clermont Auvergne on Saturday, October 16.

"We approach the competition which is unknown to the club, even though some players have already played in the Heineken Cup. That experience will be very important," said captain Lionel Nallet.

"In previous years when we have watched the Heineken Cup, we have always wanted to be a part of it.

"This year we have a bit more experience as a team. We are still in a building phase. We have only been in the Top 14 for a year but now we are getting our bearings.

"The intensity of this tournament is a notch above and the main difference in the Heineken Cup is that if you make a little mistake you are almost out."

Racing-Metro face Leinster at the RDS Stadium on Saturday before taking on Clermont a week later. English side Saracens are the opposition in December in the back-to-back fixtures in Rounds 3 and 4.