Both of Mercedes' race drivers are out of action at present. World champion Lewis Hamilton kicked off the team's four-day test at Barcelona early on Thursday, but had to retire after a handful of la...

Both of Mercedes' race drivers are out of action at present.

World champion Lewis Hamilton kicked off the team's four-day test at Barcelona early on Thursday, but had to retire after a handful of laps, reportedly with a fever.

Curiously, he was replaced not by his teammate Nico Rosberg, but by reserve driver Pascal Wehrlein, who at the time was happily circulating for the customer team Force India.

Germany's Auto Motor und Sport knows why: Rosberg is also out of action as he suffers from an inflamed nerve in his neck.

Correspondent Michael Schmidt said the 29-year-old has been "advised by doctors to completely recover from the inflammation, lest the problem recurs".

Rosberg suffering inflamed nerve in neck - report