Irvine knows all about the ferocity of games against pumped up provincial teams from his three tours as a player with the Lions in 1974, 1977 and 1980 and realises that Wednesday night will be a special occasion for the Force players.
"We have to be realistic, while it was a good start against the Barbarians the game in Perth is going to be a different match all together. Western Force will be well structured, they've played together for the last six months and they only get a crack at the Lions once in every 12 years," said Irvine.
"As Warren Gatland would say, their heads will be bouncing off the walls in their dressing room. They will want to get out and upset us.
"We are expecting a much more fierce physical contest and it will probably be a faster game because it will be a fast track and the ball will be dry. Our running fitness will be tested, although I'm sure we are up for it and we are looking forward to it."
The eight try victory in Hong Kong was a sound start and Irvine picked out acting skipper Paul O'Connell for some special praise after he scored his first try in 12 matches in a Lions jersey.
"Paul O'Connell did really well. The season at home is very long and hard, but because he was injured early on he is really fresh and invigorated, He had one of his best games in a Lions jersey and he is running around like a young thing," said Irvine.
"There were 11 new starts in the starting 15 and 16 in the whole squad. There is a huge amount of pride and respect for the jersey from all the players and we are very please where we are.
"I was delighted with the performance because the conditions were tough and had some of our off-loads stuck in the game we might have scored an extra 15-20 points. Our fitness levels were first class and the three weeks preparation paid off very well.
"The team spirit is excellent and the lads have all hit it off well together. These lads are dedicated professionals and they really look after their bodies and they are in very good shape.
"The tour really got off to a great start from a spectacle and entertainment point of view. The atmosphere was electric and I felt the whole spectacle and theatre was tremendous. If the other games are as good as that then we are in for a super tour."