Colombo: India's bid to become the top team in the world suffered a big jolt on Thursday after Gautam Gambhir was ruled out of the tri-series due to a groin injury.

Gambhir stayed in the dressing room as the others had a gruelling nets session at the Max Cricket Academy here. Delhi middle-order batsman Virat Kohli has been called in as replacement and Gambhir will be flying back home, having been adviced a minimum 10 days of rest.

Gambhir, it seems, was carrying the injury from the Corporate Trophy itself. "I am not sure but I think he got this injury during the Corporate Trophy semifinal," revealed skipper MS Dhoni.

Dinesh Karthik will now be expected to open the batting with Sachin Tendulkar against the Kiwis on Friday. Karthik had opened the innings in the West Indies too, notching up scores of 67, 4 and 47.

"Gambhir's injury at this stage is a huge blow but we can't do much about it," Dhoni said, adding that this would be "an opportunity for the others to prove themselves at the international level".

"In such circumstances someone or the other has always stood up and said that they can do the job. This time it is Karthik. He has opened the batting for us in ODIs and Tests before so I think he will be able to do the job this time also. He looked in fine nick at the nets on Thursday," added Dhoni.

Gambhir's injury, though, makes the recalled Rahul Dravid's presence at No. 3 more crucial, especially if India lose the toss and have to bat under lights: Conditions at the Premadasa have ensured that the last 13 matches have been virtually decided on the toss.

"Dravid is the ideal guy to bat in that position. As we have seen in the last two series here, it is very difficult to bat under lights. It is in such conditions that a batsman like Dravid comes in very handy," said Dhoni. Friday's match might also see Mumbai all-rounder Abhishek Nayar making his debut. Nayar can fill in as the third seamer as India look to go in with four bowlers - three seamers and one spinner - with part-timers Yuvraj Singh, Suresh Raina and Yusuf Pathan also turning their arm over.

"We are not going with five specialist bowlers as our part-timers have been doing a fabulous job. Viru is not there but Yuvi, Yusuf and Raina have all showed that they bowl," added the skipper.

Having lost the first game against Sri Lanka, there will be big pressure on the New Zealanders too. But even though Shane Bond's return might add zing to their pace attack, there are not many takers for an upset.