Kai Havertz "just wants to be a nice player", according to Glenn Hoddle, who says the Chelsea midfielder "has to be a little more assertive".
Havertz has struggled for form since completing a £70 million ($92m) move to Stamford Bridge from Bayer Leverkusen in September.
The 21-year-old built up a reputation as one of the best young playmakers in Europe during his time at Bay Arena, but has been unable to reach the same heights during his first few months at Chelsea.
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A modest tally of four goals through 17 appearances has done little to convince supporters he was worth such a huge investment in the summer transfer market, with his latest sub-par display coming during a 2-1 defeat at Wolves last week.