Jonas Gutierrez has said the week after Newcastle's 3-0 derby defeat to Sunderland was his lowest on Tyneside.
Newcastle were humiliated by their fierce rivals on Sunday, and Gutierrez said it felt worse than the aftermath of the club's relegation to the Championship in 2009.
"I think it's the worst week since I've been at the club," he told the Journal. "To lose like that at home is something that I feel will make all of the team sad and the city is sad, too. They are not enjoying this week.
"Of course, to be relegated is hard, but this has been a worse week. To lose the derbies is something very painful for the squad.
"I haven't been out because of the result. I have stayed at home. It's the same with all the squad.
"The more positive thing to do is to keep calm and stay at home, because what can you say to the fans when they ask you what happened? It's about action, not words. Sunday is done now."
The Magpies are not yet guaranteed Premier League survival, sitting just five points above the relegation zone in 13th place.
Gutierrez believes the club must now concentrate on securing their top-flight status, starting with the game against West Bromwich Albion on Saturday.
"We have to focus on the last five games that we have in this season because we are in a situation that isn't easy, but it's not the worst," he said.
"There are many teams fighting to take the points to make sure they are in a good position in the final league places.
"We have a good opportunity now against West Brom to go away and get three points."
Meanwhile, defender Mapou Yanga-Mbiwa believes responsibility for the derby defeat does not lie with the manager, Alan Pardew.
The France international told the Evening Chronicle: "I believe the responsibility for performances and results lies with the players.
"We have to take care of winning the next game. The coaches and manager will help us, of course, but we need to take responsibility to show that we want to win the next game and keep the club in the Premier League. Everyone needs to be ready now."