To make matters worse, Chelsea fly to Foxboro for a friendly, during which a top player is injured:
According to the linked article, if Chelsea win the Europa League, RB Salzburg qualify for the group stage of the next Champions League!
I was under the impression that if Chelsea wins, it would benefit the French league, currently Lyon.
Arsenal and Chelsea are in the Europa League final and the winners will qualify for next season's Champions League group stages.
If the winners finish outside the top four in the Premier League (which is almost certainly the case for Arsenal), it will mean five English teams will be in the Champions League.
However if they do finish in the top four (as Chelsea have), then England will not get an extra spot. The team who finish third in the fifth-ranked league - France - will go into the Champions League group stages instead of the qualifiers.
Even if the winners have already qualified for the Champions League through league position, however, there is no spot for the beaten finalists.