Saracens will play at Twickenham if they reach this season's Heineken Cup semi-finals.
The reigning Aviva Premiership champions can book a last-four place with victory over Clermont Auvergne at Vicarage Road on Sunday.
And tournament organisers have confirmed that if they triumph, Twickenham will stage Saracens' semi-final on Sunday, April 29, against holders Leinster or sole Welsh survivors Cardiff Blues.
Should Clermont topple Saracens, then the semi-final will be at Stade Chaban-Delmas in Bordeaux.
The other semi-final a day earlier - Munster or Ulster versus Edinburgh or Toulouse - has been confirmed for Dublin's Aviva Stadium.
The final is at Twickenham on Saturday, May 19.
The Amlin Challenge Cup semi-finals - Toulon or Harlequins against Stade Francais or Exeter and Wasps or Biarritz versus Brive or Scarlets - are scheduled for, respectively, April 27 and April 28 or 29, at the winners' home grounds.