And he is looking forward to the re-run against group opponents Perpignan, warning it will be a very different game to either of the times the pair have already played each other this season.
“We are really enjoying our rugby at the moment, it is a great time to be at London Irish,” said Casey.
“It is massive for the club to be in the quarter-finals, it really puts us on the European map. We set this as as one of our goals at the start of the season, we believed we could achieve it and we have.
“We would not have been that well known as a club so to reach the quarter-finals is massive for the players, the management, the board and also our fantastic fans.
“They are very formidable opponents, probably consistently one of the toughest sides in Europe over the last few years. We did very well to beat them at home and were beaten away from home so it will be difficult for us.
“It will be a humdinger of a game. Hopefully it is a sign of things to come for London Irish.”