Lewis Hamilton and Valtteri Bottas have played down suggestions their relationship could break down.

Some, including Mercedes boss Toto Wolff, have warned that given the closeness of their championship battle so far, there are signs the relationship could go the way of the toxic Hamilton-Nico Rosberg pairing.

"I don't think it's appropriate to talk about it, but there were things that happened in the background that you don't know about," said Hamilton, when asked what went wrong with Rosberg.

It is believed Hamilton is referring specifically to actions taken by Rosberg, arguing that in contrast, the atmosphere inside Mercedes is "excellent".

Barcelona is the scene of the crescendo of the Hamilton-Rosberg relationship collapse, when they collided at the start of the 2016 Spanish GP.

"Of course I remember it, but I do not believe or expect that it will happen again," said Bottas.

Hamilton agrees.

"Since then I have matured both as a driver and as a human being, and I'm a better team player," he said.

"We both have a lot of respect for each other, and that's how it will stay."

However, he risked irritating Bottas by saying a big reason for the Finn's surge in form in 2019 is due to his work with a new engineer.

"He is working with my second engineer," Hamilton said. "He became Valtteri's main engineer and it's a good help for him. You would expect him to take a step forward.

"I have a new engineer, and it takes time to build a relationship like that," he added. "It will come, it's still early."

And Hamilton also warned Bottas that he will not be quite as "friendly" as he was at the start in Baku a fortnight ago.

"I will be respectful and we are not going to touch, but as far as giving up a position is concerned, that will not happen again," he said.