Sunderland manager Martin O'Neill denied his side are lacking in confidence after they were knocked out of the Capital One Cup by local rivals Middlesbrough at the Stadium of Light.
Scott McDonald's first-half strike earned Boro a quarter-final place in a hard-fought Wear-Tees derby as Sunderland again drew a blank up front in the 1-0 defeat.
"It was an opportunity for us to try and get into the quarter finals of the competition and we didn't play well enough and we didn't deserve to go through," O'Neill told reporters.
McDonald, who was handed a start after he scored both of the goals in last weekend's 2-1 npower Championship win over Bolton from the bench, scrambled the ball home from six yards at the near post in the 39th minute.
It was enough for Middlesbrough to progress as Sunderland lacked the cutting edge that has seen them draw six of their eight Barclays Premier League games and only score six league goals so far this season.
O'Neill added: "It was really disappointing. We started off brightly in the game but Middlesbrough forced their way into the game and in truth we didn't create enough. Eventually we didn't have enough confidence but not at the start of the game and not on the back of a strong draw on Saturday (against Stoke).
"I thought it was quite the opposite but if you're not playing well enough that can drain you and you can start playing the wrong options. Collectively we were not good enough to go through and that's very disappointing indeed."
Boro boss Tony Mowbray believes O'Neill will fix Sunderland's goal scoring problems after watching them draw a blank against his side on their home turf.
"I have total respect for Martin and his team," Mowbray said.
"I'm sure he's scratching his head as to why they've not scored as many goals as he'd want. They've got a lot of attacking prowess and a lot of players who can score goals. I'm sure Martin will find the answer to the conundrum he's got at the moment and find more goals."