United are said to be in talks about taking Dembele on-loan for the season.
Asked why the France attacker wasn't considered last night, Koeman insisted: “It is not true.
"If I had thought about it, I wouldn't have summoned him. Pedri and (Francisco) Trincao are players who can contribute more than Ousmane defensively and that's why it was my decision."
The latest is Barca are willing to send Dembele to Old Trafford if United agree to cover 100 per cent of his wages.