Cotter's side completed the double over Saracens when the two sides met in the pool stage of the 2010/11 tournament but Cotter believes that will play no part in this fixture and knows his side face a stern challenge.
"The draw has been good for us, it will be a huge game," he said.
"We will play against the English Champions in their home ground and Saracens have a very large and impressive squad.
"We have improved a lot but we need to forget about our two pool games against them last season. They didn't have a lot of play for and they are a much better team this year.
"The new half-backs have made a different and John (Smit) has helped take them to a new level and we know its going to be tough.
"We have two month to prepare for this big game.
"We are going to target this date to be at our very best. Play away will be difficult but we know we can count on our supports to get behind us
"And we will do everything possible to reward them with a home semi-final which would be great reward for them."