Williams' decision about its 2012 driver lineup is nearing.
Writing in Germany's Speed Week, Peter Hesseler said the famous British team "plans to decide within a week" who will be driving the two cars next season.
"This is what shareholder Toto Wolff is saying," he revealed.
On the face of it, Pastor Maldonado's seat is safe, but reports say his lucrative backing by state owned oil company PDVSA is set to be investigated by the Venezuelan parliament.
In reality, it is Rubens Barrichello who is the most worried, with a trio of candidates including Kimi Raikkonen, Adrian Sutil and Valterri Bottas all reportedly in the running.
Italy's Autosprint reports that Raikkonen is "ready to sign" a one-season deal so that he is free to switch to Mercedes, presumably to replace Michael Schumacher, in 2013.
The report said Dutchman Giedo van der Garde is also a contender.