Bolton's summer signing Daniel Braaten was disappointed with his Premier League debut against Fulham.
The Norwegian winger came on for the final 18 minutes at Craven Cottage, but was unable to prevent Bolton from falling to a 2-1 defeat.
Braaten was not happy with the way he played and is looking for improvement when Bolton face Portsmouth at the weekend.
"I was too weak in my challenges, I have to work on that," Braaten told Dagbladet.
Despite Braaten's criticism of himself, Sammy Lee has been satisfied with the 25-year-old's efforts since his arrival from Rosenborg.
"He has impressed me in training, but it would be wrong of me to throw him into this too early," Lee said.
"He got some minutes (against Fulham) and I thought he did well."