Manchester United midfielder Park Ji-sung admits his performances so far this season have left him far from happy.
After his World Cup exertions with South Korea, Park has struggled to find any kind of form since his return to Old Trafford.
His first-half display in Valencia last night was particularly poor as the 29-year-old repeatedly gave away possession when Sir Alex Ferguson had implored his team to retain it.
At one point, the demanding United manager delivered a stinging volley at Park to try to trigger some improvement.
The move did actually succeed and Park completed the full 90 minutes of the excellent 1-0 win at the Mestalla stadium.
But he is still not happy with his own contribution.
"I am not satisfied with my performances this season," he said.
"I don't know why my performances have not been good. Maybe I was not ready for the season.
"But mentally I have been weak and I have to improve.
"In the first-half last night my performance was bad but at least the second was better."
Compared to many of his team-mates, Park is still lacking minutes.
Last night represented the first occasion he had completed an entire game this season, although at least in coming through his third outing in a week, he is starting to get some continuity.
"It is always difficult to get the balance," Park said.
"I missed a couple of games and then played again, although since I joined Manchester United it has been like that so I should know how to deal with it."
United will be hoping last night's success kick-starts their season.
Their second victory in 19 visits to Spain to face Spanish opposition, Javier Hernandez's late strike put them on top of Group C - above Rangers on alphabetical order - and in line for a place in the last 16 given they now face back-to-back encounters with Bursaspor, the Turkish champions who are yet to collect a point so far.
United have also proved they can compete without Wayne Rooney, who is set for a three-week stint on the sidelines with an ankle injury he had checked out in Manchester yesterday.
Although most of Rooney's absence is covered by the forthcoming international break, he will sit out Saturday's trip to Sunderland and possibly the home encounter with West Brom a fortnight later and the first of those two encounters with Bursaspor on October 20.
Yet Park does not feel United should be concerned.
"Throughout Manchester United's history we always come up with answers to problems," he said.
"Big stars come and go but still the team keep producing the same performances.
"We just concentrate on that to make sure we show our quality on the pitch."