Each side has two wins to show from the previous four encounters, whilst the teams have met just once before in round one: in 1999 when the Exiles won 28-23 at Vicarage Road.
Saracens have won just once in their last four matches in the opening weekend Twickenham double header: 29-12 over Wasps in 2007. Sarries have lost their last three games in the Guinness Premiership since a 19-14 win over Wasps at Vicarage Road on 29 March.
London Irish have won four of the five previous games they have played in the round one London double header, with their only previous loss being 27-35 to Harlequins in 2007. Last year’s Guinness Premiership finalists won the Middlesex Sevens here three weeks ago.
Referee: Dave Pearson (127th Premiership game)