After playing a starring role in the thumping Premier League win over Crystal Palace last weekend, Thomas Tuchel laid down the gauntlet to Kai Havertz.
Havertz opened the scoring for Chelsea while also grabbing an assist for Christian Pulisic's first goal of the game at Selhurst Park. The German was influential as the Blues kept up their top-four charge.
But Havertz will be the first to recognise that more is needed from him, having only shown glimpses of his best following his £89million move from Bayer Leverkusen last summer.