The two sides are no strangers to each other having met in Pool 2 with Saracens winning 28-23 at Vicarage Road and then the sides playing out a 6-6 draw at Hughenden. Now a European Challenge Cup semi-final place goes on the line at Vicarage Road.
"We will go in as massive underdogs – although we know that we can take Saracens on our day," said Sean. "Saracens are a quality side with some fantastic players and coach Alan Gaffney has got them playing some great rugby.
"They are one of the form teams in Britain at the moment and it is going to need a huge effort from us on Sunday because Saracens' strengths run throughout the side – they are a pretty formidable outfit. They have a good scrum and ball carriers and know how to pressurise sides while not making many mistakes themselves."
But Sean believes that Scottish pride can be a major influence, adding: "There is a great buzz around the club for this quarter-final. We know that on our day we can beat anyone and what better day than 1 April to book a place in the semi-finals.
"This match means a huge amount to everyone connected with the Glasgow team, Glasgow and also to Scottish rugby. We need to make a statement of intent, show we are moving forward and, while it will not be easy, it can be done.
"It is going to be touch and go with a couple of players regarding their fitness but it is good that we have had some time off and did not have a game last weekend. The players will be better for the break and we have been able to concentrate and focus on preparing for the Saracens quarter-final."