Arsenal were drawn against Napoli on Friday in the pick of the Europa League quarter-finals. Unai Emery's side advanced to the last eight after overturning a 3-1 first leg defeat to beat Rennes 4-3 on aggregate. Gabon international Pierre-Emerick Aubameyang bagged a brace in the 3-0 victory at the Emirates.
Whoever emerges from that tie will go on to a semi-final against the winners of an all-Spanish quarter-final between Valencia and Villarreal.
Both La Liga sides defeated Russian opposition in the last 16. Valencia saw off Krasnodar and Villarreal knocked out Zenit Saint Petersburg.
Chelsea, winners of the Europa League in 2013, will be deemed favourites against Slavia Prague. But the west Londoners have been inconsistent this campaign under coach Maurizio Sarri.
Slavia lead the Czech top flight and thrillingly disposed of a much fancied Sevilla side in the last 16 second leg.
With the aggregate score at 5-5 on Thursday night at the Sinobo Stadium and the Spaniards heading into the quarter-finals on the away goals rule, Ibrahim Traore scored in the dying seconds to send the hosts through.
Should Slavia unleash similar heroics against Chelsea, a semi-final awaits against either Benfica or Eintracht Frankfurt.
