It was a bruising day for Newcastle United and their new owners, an FA Cup exit to a League One side followed by news of a legal claim from Mike Ashley against Amanda Staveley and her husband Mehrdad Ghodoussi.

The details of the High Court action have not been made public but Ashley’s intention to sue the club’s co-owners will be an unhelpful distraction at a time when focus is needed elsewhere.

Primarily, Staveley must sign a striker before Saturday’s visit of relegation rivals Watford or risk losing a match that ranks as the biggest of their tenure to date.

She sat alongside Newcastle chairman Yasir Al-Rumayyan as Eddie Howe’s side were beaten 1-0 by Cambridge.

The ownership team felt it necessary to visit the dressing room and Howe’s office afterwards. They offered nothing but support for the players and head coach, but backing in the transfer market will be vital.

Newcastle do not have a striker available. Top scorer Callum Wilson is facing at least two months out and back-up Dwight Gayle is also sidelined.

Ashley's legal claim includes both Staveley (right) and her husband Mehrdad Ghodoussi (left) 

Goalkeeper Martin Dubravka limped away from the stadium on Saturday and there was a heart-stopping moment when £12million debutant Kieran Trippier was caught on the ankle and left squirming on the ground.

Then came news of Ashley’s legal action. Staveley and Ghodoussi are yet to be served with proceedings but they are aware of the case.

Their relationship with the former owner appeared to be good after working together to complete the £305million Saudi-backed takeover in October.

Ashley’s final connection to the club was removed last month when the Sports Direct signs inside St James’ Park were taken down.

Representatives of Staveley and Ashley have declined to comment on the legal case.

Ashley, meanwhile, has been linked with a £50million buyout of Derby County