Hannover 96 await the winners of the second round qualifying match between the Saints and NK Široki Brijeg.
The sides drew 1-1 last night and meet again next week at Richmond Park to see who will progress to the next round.
Hannover 96 made it to the Quarter-Finals of last season's Europa League only to lose out to Atlético Madrid.
They qualified for this year's competition having finished 7th in last season's Bundesliga.
The third round qualifying matches will be played on August 2nd and 9th with the winners progressing to the play-off draw on 10 August.