Stuck doubts Kubica fit to race
"I am not surprised that he wants to drive," Stuck is quoted as saying by Bild newspaper, after Pole Kubica, 22, left hospital at noon on Monday.
"He is extremely ambitious and we all want to drive. But desire and reality sometimes lie far apart."
Kubica's 230kph impact with an unprotected concrete wall on Sunday left him with mild concussion and a sore ankle.
And given that he briefly lost consciousness as he was being attended by doctors, Stuck said FIA officials are unlikely to agree with physicians in the Montreal hospital who declared Kubica fit to race.
"I can't imagine that they will expose him to the risk — Indianapolis is not a playground."
BMW-Sauber has until 4pm (local) on Thursday to nominate its drivers for the US grand prix.