Saracens and new England squad member Joel Tomkins is braced for a stern test on Friday against Toulouse at Wembley Stadium.
Tomkins, who was one of three uncapped centres in Stuart Lancaster's squad for the upcoming November Internationals, is set to compete with Gloucester centre Henry Trinder for the outside centre berth.
The former Rugby League player is looking forward to testing himself against one of Europe's greatest sides, highlighting the intensity of the Heineken Cup as one of the reasons why he swapped codes.
"It is massive," Tomkins told the Telegraph.
"It is going to be really exciting to play at Wembley. It is the national stadium and we have sold over 50,000 tickets and hopefully we can feed off the big crowd.
"This is one of the reasons since I came to rugby union because you get these massive European clashes.
"Toulouse are historically the most successful side in the Heineken Cup and we know it is going to be a major test.
"They have got a really good squad of players but then so have we and we have got to be confident in our own ability to take our game plan to them and impose it on them."
Reflecting on his selection by Lancaster, Tomkins cited the phone call he received on Tuesday from the England coach as the "proudest" yet, but was now targeting bigger and better achievements.
"I would definitely say it is the proudest day of my rugby union career so far," added Tomkins.
"It is probably better when you finish to look back at what you have achieved and then you can work out what the proudest moments were but it is definitely a big day and I'm really pleased to be in the squad.
"But the hard work is just about to start. I want to get in there and get my head down and try to earn a place in the team and if I can do that, then I will be really proud."