Mercedes are considering Fernando Alonso as a replacement for the world champion Nico Rosberg, who retired from the sport suddenly on Friday.

Alonso still has a year left to run on his contract at McLaren but that has not stopped the Mercedes head of motorsport, Toto Wolff, from publicly speculating about tempting the two-times world champion to his team.

“You have to consider Fernando,” Wolff told Sky Sports. “He is a driver I respect a lot. He combines talent, speed and experience. It’s all there. But he is in a contract with McLaren-Honda at the moment and we just need to weigh all the other options up.”

Testing is due to start in February and Mercedes – thrown by the speed of Rosberg’s retirement – will need to act quickly in order to secure a new driver to race alongside Lewis Hamilton. Alonso has teamed up with Hamilton in the past at McLaren but they endured a difficult relationship, with Alonso eventually leaving at the end of the 2007 season after the pair had stopped talking to one another.

The young German former Mercedes test driver Pascal Wehrlein, 22, remains a more realistic option for Wolff, who insists both his drivers will share top billing. He could be used to keep the Mercedes seat warm for Alonso for a year until his contract comes up. Another possibility is the Williams driver Valtteri Bottas, the Finn who is managed by Wolff.

“We will maintain the system we have,” Wolff said. “Both drivers will have equal status and equal opportunity to the best of our abilities. We owe it to the fans. You can’t have a pecking order.”