It's rumored that Ferrari took care of Hulkenberg's unpaid salary, so that he could not be hired by Lotus.
Nov.14 (GMM) Ferrari stopped Nico Hulkenberg from joining Lotus for the last two Grands Prix of 2013.
That is the hot rumour in the Austin paddock, as the two teams battle over millions for third place in the constructors' championship.
The first rumour was that Ferrari, who have signed Kimi Raikkonen for 2014, may have encouraged the Finn to arrange early back surgery and miss Austin and Brazil.
Now, it is being reported that Lotus approached Hulkenberg to replace the Finn, only to find surprisingly that the German is still locked into his Sauber contract.
It was believed Sauber had earlier breached Hulkenberg's 2013 deal by not paying him.
But Hulkenberg's manager Werner Heinz told Sport1 radio on Wednesday that moving to Lotus for the last two races would have meant breaking a valid contract.
"Sure, it would have meant that," he said. "But I also don't think Sauber would have put obstacles in the way."
The big rumour now is that the obstacle was in fact put in the way by Ferrari.
"Apparently," read a report in the German newspaper Bild, "Ferrari took care of Hulkenberg's unpaid salary, so that he could not be hired by Lotus."
Sauber, a traditional ally of the Italian marque, is powered by Ferrari engines.
Indeed, it is believed Hulkenberg came so close to moving to Lotus for Austin and Brazil that he even had a seat fitting at Enstone this week.
"One can only speculate about the reason for the change of plans," read a report in Germany's Auto Motor und Sport.
"In Austin on Wednesday it was rumoured that Sauber paid Hulkenberg's salary at the last minute."
A report on the Italian website blogf1.it added: "According to our sources, the money came straight from Maranello."