I think not only Arsenal will experience fatigue before facing Chelsea but Chelsea players will also experience it. In the UCL, Chelsea will face Dynamo Zagreb and in the Europa League, Arsenal will face Zurich. so that when the two meet (Arsenal vs Chelsea) then the chances of each player experiencing fatigue are huge. I think the odds of winning for both are 50:50, I will be careful in placing my bets in this match later.
Of course both will experience fatigue but it also depends on the coach in managing the team so that the main players don't get tired, but I'm sure Arteta can do it because Arsenal have to be consistent to win the title. Chelsea is also not an easy opponent to beat so Arteta will have to think about it early on to successfully steal points in this match, but to bet I'm also not sure, although Chelsea previously lost easy against Brighton not necessarily lost easy again vs Arsenal. This match will be interesting.
Arsenal and Chelsea players both have the chances of getting fatigue. The featuring of English Premier League this time around is so squeezed together there is no much time for players to rest, could it be because of the break that was given during Queen's death?
If I were Arsenal coach I will play second 11 for the Europa match then watch the situation before second-half and then reserve the remaining of the players for English Premier League with Chelsea, that should be the most important title for Arsenal this season.