Newcastle United boss Glenn Roeder was furious about the way his side threw away three points as they slipped to a 2-1 defeat against Bolton Wanderers on Sunday.
A 19th-minute Shola Ameobi spot-kick put the Magpies ahead at St James' Park, but their performance dipped after the break and El Hadji Diouf netted twice in as many minutes shortly before the hour mark to clinch the points for Bolton.
The result extended Newcastle's winless run to four Premiership matches and Roeder is growing increasingly concerned about his team's prospects for the season.
"The manner of the defeat greatly concerns me and was typical of the year we have had," said Roeder.
"We keep shooting ourselves in the foot and it has to stop because for 60 minutes I thought we were terrific - the first half particularly.
"It was unacceptable defending and the only thing we can do is get back on the training ground and work hard on those situations."
He added: "I'm concerned and the players are concerned and we had a long talk in the dressing room after the game.
"Now is the time to stand up and be counted and show that we are mentally tough."