Frank Lampard has urged patience with Kai Havertz after suggesting the playmaker may need a whole season to adapt to the Premier League after he was hauled off in Chelsea's 1-0 defeat at Everton.
The 21-year-old joined Chelsea in a £70 million ($93m) deal, including add-ons, from Bayer Leverkusen in the summer but put in an underwhelming display at Goodison Park before he was substituted for Tammy Abraham in the 68th minute.
Part of the Germany international's struggles have come after he suffered from symptoms of coronavirus that left him unwell and unable to train for a fortnight.