BARCELONA, Spain -- Manor driver Pascal Wehrlein says he feels ready for a Mercedes drive in 2017 after another day of testing for the world champions in Spain.

Wehrlein was a late change to the driver line-up on Wednesday, stepping in for Mercedes as it wanted an experienced driver to complete its testing programme for the week instead of GP3 champion Esteban Ocon. It came at a time of speculation about Mercedes' 2017 driver line-up after Italian reports of Nico Rosberg "flirting" with Ferrari over a drive next year.

As Mercedes reserve driver, Wehrlein would be a strong candidate to step up to the team in that instance.

Asked if he would be ready to race in 2017, he said: "Yes I would be ready."

Wehrlein, who tested for Manor on Tuesday before being told at 8pm he would get another day with the world champions on Wednesday, feels like he is always showcasing his talents to Mercedes whenever he is driving a Formula One car.

"You always are [auditioning], you cannot relax, step back, hope or be sure of what happens next year or the next years so you always need to push, always need to push yourself and make the best out of it."

The German-Mauritian driver is refusing to get too carried away with the future when he has a full campaign with Manor to focus on this season.

"I don't know. I'm pushing as hard as I can, that I can't win a race this year is clear. You never know what happens in the future. At the moment, I just focus on my job this year, I want to learn as much as possible and get the best results out of the car. Other decisions, I'm the wrong person."