Barcelona face Valencia on Sunday and it could be Kun Aguero’s debut after injury.
He scored in a behind closed doors friendly the club had in midweek against Cornella and Koeman was asked about him on Saturday.
“He has improved a lot recently. On Wednesday he played 20-25 minutes. He lacks match fitness, physical tone. That’s what he’ll get from playing.
“It’s possible he’s on the squad list tomorrow.”
Koeman has been missing strikers, including Ansu Fati, who has only recently returned, and Ousmane Dembele.
On Kun, he added: “He’s a player who can give a lot to the team. What’s important is that he’s fine physically. Like with Ansu Fati, he’ll keep improving in this aspect.”