Newcastle United manager Alan Pardew said the effects of last week's encounter with Benfica took it's toll on his side during their 3-0 derby defeat to Sunderland.
The Magpies exited the Europa League at the hands of the Portuguese giants on Thursday night, less than three days before hosting their North East rivals in Sunday's lunchtime kick-off. The Black Cats won the match with goals from Stephane Sessegnon, Adam Johnson and David Vaughan.
Speaking after the game, Pardew said: "It was a tough day really. I thought they looked like a team who had worked all week on us, and we looked like a team who had a really tough game on Thursday night."
He added: "Unfortunately it turned out to be a great day for Sunderland, and an awful day for us."
Police have released a breakdown of those arrested before, during and after Sunday's derby match as they continue to appeal for information.
Newcastle United have released a statement saying they are "embarrassed and appalled" by the behaviour of fans who clashed with police.
A police horse seen being punched by a football fan is "safe and well" this morning, its police force said.