Southampton have been drawn against Vitesse in the third qualifying round of the Europa League, while West Ham United could face Inverness Caledonian Thistle in the next phase.
Ronald Koeman's side, who finished seventh in the Premier League last season, will go up against Chelsea's feeder club.
The Dutch outfit is also the club that gave Koeman his first stint as manager following his assistant roles with the Netherlands national team and Barcelona.
Meanwhile, the Hammers have a 1-0 lead over Birkirkara in the second qualifying round, but should they progress, Slaven Bilic's side will face either Inverness or FC Astra.
The first legs will be played on July 30, with the return fixture on August 6, just two days before the domestic season begins.