The two sides will go head-to-head in their third-round replay at Griffin Park after the Shrimpers came back from two goals down to salvage a 2-2 draw in the initial meeting.
Southend knocked their npower League One opponents out of the Johnstone's Paint Trophy at the start of December and are now gunning for a cup double for the right to face the reigning European champions and FA Cup holders, yet defender Cresswell is focused firmly on Tuesday night's tie.
"Brentford are a good side, they haven't lost at home since August," he told Press Association Sport.
"And I think the last team who beat them at all was us last month, so it's going to be a tough game.
"Hopefully we can put one over on them and then obviously there's that tie at the end of that which everyone's thinking about. But first and foremost it's all about Brentford."
Cresswell did however allow himself to get a little excited when seeing Chelsea's name emerge from the hat.
"Obviously my first reaction was `bloody hell, that's a fantastic draw'. It's the best draw I've every had in the FA Cup, that's for sure," he added.
"But, like I say, we can't get carried away because we've got a very tough game coming up against Brentford, they're a good team and by no means are they just going to turn up and let us win, they've seen the draw and they want that big tie as well."