Ferencvaros 0-3 Barcelona.
Dembele scored and assisted in Hungary to earn special praise from Koeman.
The boss is pleased with the competition for places in his attacking line.
“Dembele is a great player,” Ronald Koeman told the post-Ferencvaros, as quoted by Goal.
“He is very fast, he plays with both legs and is physically very well. For the coach, it is difficult to make decisions when people like Dembele are playing as they are.
“There is a lot of competition in attack. You can see that we have a good squad and we have been able to let several players rest.
“Those who have played have shown that there is competition, and want to play well and create chances.”
Ousmane Dembele set up Martin Braithwaite’s goal before scoring himself from the penalty spot in Barcelona’s 3-0 Champions League win in Hungary on Wednesday.
The Frenchman is now expected to start in the La Liga clash at Cadiz on Saturday.