Koeman left Puig out of the squad for Saturday night's Gamper Trophy clash against Elche after advising the 20-year-old to seek a new team for the 2020-21 season.
But after the 1-0 win, the Dutchman told Barca TV: "It's not true that I'm not counting on him. I spoke to him yesterday before training and I'm clear that the young players have to play and I told that to him.
"That can apply to [Carles] Alena and Pedri too. Youngsters like Riqui have to participate and I told him it would be very difficult for him here. because he will have a lot of competition.
"I told him he has future here and what we think is the best way for him to triumph at Barca."
Asked if a loan was the best option, he said: "It's a possibility, but that could be of value to other young players. Lads who are 20 years old have to play and cannot be stalled.
"We have made conclusions in these three weeks and Riqui has too much competition."