Michael Schumacher has refused to deny speculation linking him to a racing return with Mercedes GP next year.
Competing at a Brazilian kart event last weekend, the 40-year-old responded to questions about Formula One by saying: "Right now I am concentrating only on these kart races.
"Who knows? Anything can happen."
Schumacher also confirmed that the nect injury that prevented his return to F1 with Ferrari this year is now healed.
"I don't have any problems with my neck. It's 100 per cent," he said.