The draw for the Heineken Cup semi-finals to be played on the weekend of 26-27 April was made in Cardiff today.
The winners of the first quarter-final match named in each of the semi-final pairings will have home country advantage in the semi-finals.
Alan Gaffney, the Saracens director of rugby, who took his team to the number one seeds after the Pool Stages, has the possibility of facing his former Munster colleagues in a Heineken Cup semi-final.
Should his Saracens side beat the Ospreys and Munster overturn Gloucester in the quarter-finals, Gaffney faces the prospect of a battle against the side he took to one quarter-final and two semi-finals, during his three-year tenure as coach between 2002 and 2005.
"We set our stall out early this year, to be competitive with the elite of Europe," he said.
"We are realistic enough to know there are know there are no easy Pools and qualifying for the quarter-finals was a huge plus for the club.
"We are starting to achieve things this year and although the winner of our quarter-final will be home in the semi-finals we are not looking beyond our game against the Ospreys."
Heineken Cup semi-finals draw
Semi Final 1: London Irish or Perpignan v Toulouse or Cardiff Blues
Semi Final 2: Saracens or Ospreys v Gloucester or Munster