Felipe Massa has expressed surprise that his former Sauber teammate Nick Heidfeld has been left without a race seat in 2010.
The pair shared the Ferrari-powered team in 2002, but while the 28-year-old Brazilian is now a title contender with Ferrari, 32-year-old Heidfeld has had to settle for Mercedes GP's reserve driver role.
"Why has no one offered Nick Heidfeld a good cockpit?" Massa is quoted as wondering to the Swiss newspaper Blick.
"If I look at the (2010) field, Nick belongs in Formula One but not as a spare driver," he added.
In fact, Heidfeld - having spent the past four seasons with BMW-Sauber - was a genuine contender for the Mercedes race seat until Michael Schumacher decided to return to F1 in 2010.
The German told Auto Motor und Sport last week that he "could have signed" with other teams, perhaps Lotus, but opted instead to wait for Mercedes.
It is rumoured that the option of staying at Hinwil was then ruled out by Peter Sauber, because Heidfeld openly regarded the post-BMW outfit as a plan-B.
"I never said that Sauber was an alternative solution where I only needed to wave my hand and get a contract," he insists.
"My main focus was on being in a top team. There are several reasons why it didn't work out that are partly obvious and partly not.
"At McLaren I had a really good opportunity, and also at Mercedes, then things happened about which I had no control.
"When I talked to McLaren, I was fully expecting that Button is staying with Brawn," added Heidfeld.