Harlequins coach John Kingston has said that his side will not take London Irish lightly in the Big Game 5 on Saturday.
Champions Harlequins are top of the Aviva Premiership table after an impressive run of results, whilst Irish are struggling in 11th, just one point clear of bottom club Sale Sharks.
However Irish gave Harlequins a scare in the return fixture at the Madejski Stadium, with a fortunate try for Tom Casson handing the champions the victory, with Kingston acknowledging the Exiles should have won that day.
"We wont think that we will know and understand every week the key things we have to get right," said Kingston to the club website.
"We treat them the same as everyone we play, we don't judge or treat sides differently just because they have won or lost more games, we have to make sure we have everything we want in place.
"It's not about reflecting on how things are going for them or not going for them. They should have beaten us at the Madejski six weeks ago and they will know that. Expectation is a very dangerous thing."
"We are also aware it is a fantastic occasion and it is really exciting and I would be lying if I said playing there at Christmas time is not a great occasion to be involved in, I am sure the atmosphere will be fantastic again," he said.
"We have had some great moments at Twickenham over the last few years and hopefully it will be a cracking occasion and lets hope the match lives up to it, it won't be for want of trying."