Everton boss Roberto Martinez says Oumar Niasse needs to toughen up in order to handle the rigours of Premier League football, adding that English referees are unlikely to offer the same level of protection as those in Russia.
The 26-year-old arrived at Goodison Park from Lokomotiv Moscow for £13.5 million in January, but has largely struggled to adapt to life in England.
Niasse lasted for around an hour of his first ever start for the Toffees last Saturday, but Martinez says there is still a long way to go before the Senegal international begins to command a regular first team place.
The former Wigan boss, whose own future on Merseyside is far from certain, continued by saying Niasse cannot depend on referees to offer protection from the physicality of the Premier League.
As reported by the Liverpool Echo, Martinez said: "Attacking players get a bit more protection in other leagues but that’s normal, that’s what a foreign player has to go through when they come to the Premier League in general.
Niasse was voted as Russia's Player of the Year last season, and Martinez is convinced he will be able to replicate that form for Everton.
He added: "He has always been a very physical player and powerful player that can use spaces really, really well and when he arrived he was at the back of six weeks without playing with his previous team and his individual situation was very much specific and, now, he is in a completely different position.
“He has been working really, really well and got the benefit of that work and the 60 minutes at the weekend have given him an incredible feel and appetite of wanting to carry on helping the team. He is in a good frame of mind now.”