Mercedes boss Toto Wolff has said that Valtteri Bottas will have to show he is capable of matching Lewis Hamilton next season, but has backed him to do so.
While the Finn notched up the first three wins of his Formula 1 career during his first season at Silver Arrows in 2017, he struggled to consistently reach the same level which was been set on the other side of the garage.
Bottas will be once again fighting for his future at Mercedes after only been given a one-year extension and
"If he can step up and challenge Lewis he has his place among the greatest drivers in Formula 1," Wolff said in a interview with ESPN.
"That's what he has to do. If he doesn't he's going to know it and there is no excuse."
But Wolff has confidence in Bottas to show that he is made out of World Championship-winning material due to his strong mentality and the way he analyses his own performances.
"He recovered at the end of the season and he is a Finn with a strong never-give-up mentality," he added.
"Valtteri will improve his weaknesses and continue to work on his strengths.
"I expect him to come back strong with all he learning he has done during the season.
"I have no doubt we will see a better Valtteri in 2018."
When asked if Bottas may resort to mind games from Nico Rosberg's book, Wolff does not think it's in Bottas' character to respond in that way.
"That's not at all Valtteri's style," he insisted. "Valtteri wants to do it on the track in the best possible way.
"What he wants is to be benchmarked against a four-time world champion. He's brutally honest with himself."