Erling Haaland is in contention to start in Borussia Dortmund's clash with Koln on Friday but head coach Lucien Favre said the club's new striker must "keep working on his basic endurance".
The €20 million (£17m/$22m) signing from Red Bull Salzburg scored three goals on his debut as Dortmund came from behind to beat Augsburg 5-3 on Saturday.
Indeed, the 19-year-old found the net with his first touch after being introduced as a second-half substitute and has already whetted the appetite for what sort of impact he can make when he's selected from the start.