Narine, who had missed the World Cup due to his suspect action, underwent the test at the ICC-accredited Sri Ramachandra Arthroscopy and Sports Science Centre in Chennai today.
"He's gone for testing, which is good. We did not want to waste any time. I think reports will be out in next 48 hours. He's absolutely available for tomorrow's game," the two-time IPL winning KKR skipper told media on the eve of their match at Eden Gardens.
On picking him for the XI, Gambhir said: "We have not thought about it as yet. The question was about his availability and he's available. We need to discuss whether we need to risk him before the reports are out. Let's see. We still have 24 hours before the game. But having said that, we got to live with it. We will see how we go about the things tomorrow."
He however said they've enough spinners in the ranks to fill the void if left by Narine.
"If we decide on not to risk Sunil there are other players who will get an opportunity. Brad Hogg is a quality bowler and a different bowler as well, he can spin both ways. We have got Johan Botha, Cariappa and Kuldeep as well. We have got enough spinners in our ranks to trouble anyone. We have to think about our combination.