Many paddock cynics made a link between the 'injury' and the driver's now tense relationship with Lotus, after Raikkonen announced he is leaving for Ferrari next year because he hasn't been paid.
But McLaren doctor Aki Hintsa, who like Raikkonen is Finnish, confirmed to Turun Sanomat newspaper that he treated the 2007 world champion in Singapore.
Hintsa said he injected Raikkonen with cortisone.
"I am glad we were able to get him in a condition so that he could drive," he said.
Hintsa said Raikkonen has a damaged joint between a rib and the spine, causing "a lot of pain".
Raikkonen refused to say if he will definitely be ready for Korea in two weeks.
"Not for sure," he was quoted by AFP when asked if he will be recovered. "We have to see."
As ever in F1, however, the cynics and the rumour-writers are connecting the dots, recalling that earlier in Singapore, Raikkonen had hinted he is technically free to sit out the rest of 2013 due to Lotus' contractual breach.
"I like to race, obviously that's the only reason why I'm here," he had said.
Undoubtedly, the tension between Raikkonen and Lotus is building.
After the Ferrari-bound Raikkonen finished third, chief engineer Alan Permane said: "Of course it's good for the team and good for Kimi.
"But without Romain (Grosjean)'s problem, he would have beaten him (Raikkonen). So that's good for us to know," he told Turun Sanomat newspaper.
Germany's Auto Motor und Sport said Raikkonen is now only communicating with his bosses via text message.
And team owner Gerard Lopez said Lotus "didn't deserve" Raikkonen's revelation about his unpaid salary.
"I like Kimi," he told Spain's Marca newspaper, "as a driver he's brilliant, but if he's really only going to Ferrari for the pasta, I think it's Ferrari who need to be asked the questions, not us."
If Lopez sounds a little sensitive, it's because Raikkonen's comments coincide with rumours Lotus is in severe financial distress.
Lopez told Auto Motor und Sport that reports dozens of similarly unpaid engineers are also on the market are simply wrong.
"Five have gone, but we are also getting Nicolas Hennel from Ferrari, and a few more as well," he said.
"We are the only team that built a longer-wheelbase car, which is basically half a new car costing a seven-figure sum. We showed to Kimi that we are serious.
"We gave him a good car and a good environment, so the fact that he says these things now, neither us nor he deserves," added Lopez.