Goal's Chris Wheatley named the players in question set to miss out:
According to The Independent, the players were excused from training on Wednesday morning as they will not be involved on Thursday.
The news also came as manager Arsene Wenger gave an injury update on Francis Coquelin after he limped out of the 3-0 win over Bournemouth on Saturday, per Wheatley:
Goalkeeper Petr Cech, who is among those rested, has spoken of the need for Arsenal to decide on their approach to the competition this season, having won it at Chelsea in 2013, per the Evening Standard's James Olley:
"You make your decision. At Chelsea, we were really disappointed to have been knocked of the group stage [of the UEFA Champions League] but we decided that for the first time and the last time, hopefully, we play in the Europa League so we want to win.
"So you decide what you want to do—either you take it seriously and you go to win it and you give yourself the chance to do it or you give yourself different priorities and see how it goes."
The Europa League is worth taking seriously for the Gunners.
Most importantly, it's a major European honour—something a club of Arsenal's size should always aim to win, even if it isn't quite at the same level as the Champions League.
It's also arguably the best chance the north London side have of qualifying for next year's Champions League, as Manchester United did last year, such is the level of competition they face for a top-four spot in the Premier League.
That said, the Gunners can ill afford a negative result at Stamford Bridge on Sunday and need their best players fit and available, so Wenger is perhaps wise to rest them, particularly after the injury blow to Coquelin.
ESPN FC's Mattias Karen noted their need to put in a performance against Chelsea even after easing tensions slightly with a comfortable win against Bournemouth:
What's more, Arsenal should be more than capable of beating the likes of Cologne without being at full strength anyway.
The Europa League, worthwhile though it is to win, can be a gruelling slog at times. With Arsenal fortunate enough to receive a group also comprising BATE Borisov and Crvena Zvezda, it's understandable they'll look to rotate in those games to keep their players fresh and injury-free given they should still win.
Come the knockout stages, though, it could be a real misstep to not take the competition seriously.