The Welsh side have been drawn alongside reigning champions Toulon, unbeaten RaboDirect Pro12 leaders Glasgow Warriors and Premiership side Exeter Chiefs in the group stages, which starts with an assignment at Sandy Park on Sunday.
"It is a tough pool but I don't think we would have it any other way," Warburton told Sky Sports News. "With the Heineken Cup, I think it is always the case.
"We had a good game against Toulon at home last year - we lost unfortunately, but we've got a better squad this year. So you should win your home games, sneak an away win and then it opens the group up wide open then.
"With Exeter, Glasgow and Toulon, that's three top sides there who could go through and do very well in the latter stages. So we'll have to be at our best."
Warburton has recently recovered from the hamstring injury he suffered during the second British and Irish Lions Test match against Australia in June.