The club says it has suffered "more significant and longer-lasting reductions" to revenue than initially anticipated. Players and manager Mikel Arteta agreed to a 12.5% wage cut in April.
"Our main sources of income have all reduced significantly," Arsenal managing director Vinai Venkatesham and head of football Raul Sanllehi wrote in a joint statement. "Revenue from broadcasters, matchday and commercial activities have all been hit severely and these impacts will continue into at least the forthcoming 2020/21 season. ...
"We all hope there will be no 'second wave' but we also need to accept that is one of the many uncertainties ahead of us and plan accordingly."
The statement continued:
Over recent years we have consistently invested in additional staff to take the club forward but with the expected reduction of income in mind, it is now clear that we must reduce our costs further to ensure we are operating in a sustainable and responsible way, and to enable us to continue to invest in the team.
Our aim has been to protect the jobs and base salaries of our people for as long as we possibly can. Unfortunately, we have now come to the point where we are proposing 55 redundancies. ... We are now entering the required 30-day consultation period on these proposals.
The redundancies impacted some football departments at the club, as well as commercial and administrative areas, reported James Olley of ESPN FC.
Head of recruitment Francis Cagigao is reportedly among those who will leave Arsenal, according to Nick Ames and Jacob Steinberg of The Guardian. Other scouts - such as the head of U.K. scouting, Pete Clark - will apparently be affected by the cuts as well.
With the next Premier League set to start behind closed doors, the continued absence of supporters will have a major impact on the team's business model, which relies heavily on revenue generated at the Emirates Stadium.
News of the cuts comes days after Arsenal secured a valuable spot in the Europa League by capturing the FA Cup on Saturday. Winning the FA Cup also resulted in a 7.5% reduction to the agreed salary cuts.
The club - whose majority shareholder, Stan Kroenke, is worth over $8 billion - is also reportedly in the midst of negotiating a lucrative contract extension for superstar Pierre-Emerick Aubameyang.