Midfielder unhappy after loss.
Jack Colback says Sunderland just couldn't make enough of their chances as they slipped to defeat at Hartlepool in their last friendly outing.
The Black Cats went a goal down early on at Victoria Park last Friday thanks to Steve Howard's strike and couldn't find a way back into the game.
Martin O'Neill's men improved in the second half but found Pools keeper Scott Flinders in inspired form.
The stopper made a number of fine saves, including a world-class stop to keep out Fraizer Campbell's diving header.
"It was disappointing, really, and in the first half we weren't very good," Colback admitted.
"We came out in the second half and looked better - we created chances and should certainly have got back on level terms and probably gone on to win the game.
"It was a similar game to the previous year where we dominated the second half, but this time we just couldn't score.
"We should have done so and it was a disappointing result, but it was another 90 minutes for a few of the lads which is good.
"I think training in Korea has made the players stronger - training has been a lot sharper since we got back."
Meanwhile Colback has played every minute of Sunderland's pre-season programme so far, featuring against Seongnam, FC Groningen and Hartlepool.
The midfielder established himself as a mainstay in 2011-12 but says he's taking nothing for granted despite his key pre-season role.
"It's hard in pre-season to gauge the manager's plans," he explained.
"A lot of things will change before the start of the season but it's good that I've had three games."