Arsenal's Europa League clash with PSV Eindhoven on Thursday has been postponed due to a lack of police resources in the wake of Queen Elizabeth II's death last week.
A huge police operation is required in London this week with the queen to lie in state between Wednesday and her funeral on Monday, September 19.
"The UEFA Europa League tie between Arsenal FC and PSV Eindhoven, originally to be played on Thursday 15 September, has been postponed with a new date to be communicated in due course," UEFA said in a statement on Monday.
"This is due to the severe limitations on police resources and organisational issues related to the ongoing events surrounding the national mourning for Her Majesty Queen Elizabeth II."
All football matches in England and Scotland were postponed over the weekend following the death of the queen on Thursday.
Arsenal's Premier League visit to Brentford on Sunday is also in doubt due to the strain on police resources.
The Gunners face a fixture pile-up in a campaign already set to be interrupted by a first ever winter World Cup.
Outside the upcoming international break, Mikel Arteta's men are due to play every midweek before the World Cup break begins on November 13.
The group stages of UEFA's club competitions are due to finish on November 3 with the draws for the knockout stages on November 7.