"I say very clearly that Mick belongs in Formula 1," Stuck told Servus TV.
"A young driver sometimes has to throw a car away because he doesn't know what the limit is.
"Gunther Steiner has made a mistake in putting unnecessary pressure on Mick with his criticism. I say: If someone has a seat and doesn't take Mick, he's a fool.
"Once he's in the right car, he'll be a big one in the future."