There has been much speculation over who the Brackley-based team would like to see take over from the Brit, with a host of drivers being linked with a move.
Toto Wolff is exploring all options to replace Lewis HamiltonLewis Hamilton will depart Mercedes to join Ferrari next season
Antonelli takes 'big step'
The Austrian has also refused to rule out a shock move for 17-year-old sensation Andrea Kimi Antonelli.
Already on the books as a Mercedes Junior Team member, Antonelli has impressed team bosses with his performances in F2.
The Italian demonstrated his undoubted potential at last weekend's British Grand Prix, comfortably clinching victory - his first in the sport - in Saturday's sprint race.
Wolff hopes his stunning win in the rain at Silverstone will prove to be a turning point for the young star, and is backing him to keep improving as he chases a future seat in F1.
Andrea Kimi Antonelli secured his maiden win at Silverstone