Mercedes is happy to see Nick Heidfeld return to F1 with a rival team in 2011.

After losing his BMW seat, the German kicked off last season as Mercedes' reserve driver, later becoming the Pirelli test driver before returning to the grid with Sauber.

Once again for 2011, the 33-year-old was facing the prospect of a season on the sidelines, but he was believed close to agreeing to return to his reserve role with Mercedes.

Now, however, Heidfeld will be testing the new Renault at Jerez this weekend, in contention to replace his injured former BMW teammate Robert Kubica.

Mercedes' motor racing boss Norbert Haug told Auto Motor und Sport that, due to the German marque not having a race seat to offer, he will not stand in Heidfeld's way.

"If Nick has the opportunity to race somewhere, we are the last ones to throw stones in his path," he said.