Formula One world champion Nico Rosberg has warned Valtteri Bottas that it will not be easy to match Lewis Hamilton after hailing his bitter rival as "one of the best of all-time".
Bottas was formally unveiled as Hamilton's new Mercedes teammate on Tuesday, nearly seven weeks after Rosberg rocked the sporting world with his decision to retire as champion.
Rosberg finally ended his long-running losing streak to Hamilton by virtue of clinching the title at the season-ending race in Abu Dhabi in November.
But the German, who is now working for his former team as an ambassador, believes Bottas will find it a tough task to be on the same playing field as triple world champion Hamilton.
"In terms of Valtteri Bottas, I was informed of the announcement yesterday and I think it is great news for the team," Rosberg said at a Geneva sponsorship event, in which he appeared alongside Hamilton, on Wednesday.
"I am happy that they found a great solution quite quickly. I am sure he is going to do a really, really good job and he is going to blend in well.
"I am going to be sitting in front of the TV and watching the action and I look forward to seeing how Valtteri gets on, especially against Lewis, because Lewis is an awesome reference point.
"He is one of the best out there and one of the best of all-time so it is not going to be easy for him (Bottas) for sure. It will be interesting to follow."
Bottas joins Mercedes, Formula One's dominant team for the past three seasons, with just nine podium finishes under his belt and is yet to record a victory.
On paper it seems an unlikely match-up. Hamilton has three championships and, statistically at least, is the second most successful driver in the sport's history with 53 career wins.
Few people expect Bottas to beat Hamilton, but Niki Lauda, Mercedes' non- executive chairman, is not among them and he insists his new recruit can fight for the title.
"Bottas is the best man (for the job)," Lauda told German broadcaster RTL. "I believe that he can drive as fast as Nico. I believe he can win the world championship.
"We looked for a driver who fits our team. Until now we always had two top drivers who could fight for the world championship. Nico and Lewis were a fine example of that, because they were fighting head-to-head.
"In the last three years we won everything there was to win and this is why we decided to go with Bottas, as he brings experience and speed to the team.
"Both drivers can push as hard as they want, as always. This has never changed at Mercedes and it will not change in the future."