Lotus driver Kimi Raikkonen said his availability for Sunday's Korean Grand Prix will hinge on how his injured back copes with Friday's practice session.
The Finn got through the previous Formula One race in Singapore with the help of painkillers and physiotherapy, and while he is in Yeongam for Sunday's race, he is no certainty to compete.
"It's always difficult to say until I drive." Raikkonen said Thursday. "Once we drive tomorrow, I will know more."
With reserve driver David Valsecchi on standby if Raikkonen cannot take part in Saturday's qualifying, the Finn said his presence in Korea should be taken as an indication he intends to compete.
"It would pointless coming here if I didn't race," Raikkonen said.
The injury is a longstanding one, dating back to his early days in F1, and flared up again in Singapore.
"Sometimes I have to deal with the pain," Raikkonen said. "Every year you get older and you come up with more issues."
Lotus will use its new longer-wheelbase car in Friday's practice, with the intention of also using it in qualifying and Sunday's race.
"If everything goes normally we will use it, and if there are issues we can always go back (to the shorter car)," Raikkonen said.
The longer car should cure the team's problem with instability in braking and cornering, which has hampered its ability to keep up with championship front-runner Red Bull.