The Premier League duo enter the competition in the group stage as they bid to secure a spot in May’s final.
Arsenal will take on Sporting Lisbon in the group stage of the Europa League. The Gunners, last season’s semi-finalists, were drawn in Group E alongside the Portuguese club, Azerbaijan champions Qarabag and Ukrainian outfit Vorskla.
Portuguese club Sporting have started their domestic campaign unbeaten despite a troublesome summer that saw seven players cancel their contracts following an attack by fans at the training ground last season.
Arsenal boss Unai Emery has won the competition three times as manager of Sevilla.
Chelsea face some long trips on their return to Europe’s second-tier competition for the first time since they lifted the trophy in 2013. Maurizio Sarri’s Blues have been drawn with Greek side PAOK, Belarusian champions BATE Borisov and Hungarian title winners Vidi in Group L.