Gambhir (167) slammed his fourth successive century on the opening day of the second Test against Sri Lanka and Sehwag, who himself scored a blistering 131, said his younger opening partner can score another hundred in the next match.
"He (Gambhir) is best opener India had after Gavaskar. He has hit four successive Test centuries and already has eight Test centuries in 25-30 Tests. I think with the kind of form he is in, he can slam a ton in the next Test as well," Sehwag said after India piled on 417 for two on the opening day.
"He was in good form and hitting well. So we were still scoring at over three and his boundaries took the pressure off me and I could wait before playing my shots," he said.
Sehwag was seen interacting with Gambhir after the left-hander foozled a shot against Muttiah Muralitharan in the morning session.
Asked what he told his Delhi team-mate, Sehwag said, "I told him to think big. You are good enough to score four successive centuries. Stay three hours and you will automatically get a hundred."
Sehwag said India would look to pile up 700 plus runs tomorrow and put enough pressure on Sri Lanka so that the visitors crumble.
Sehwag and Gambhir were involved in a blistering 233-run opening stand that proved the bedrock of India's stunning batting display on the opening day of the second Test and the right-hander insists his teammates cannot relax or relent yet.
"We are in a positive frame of mind. We have scored a good total for opening day and scored at a good rate (4.63) to boot. Tomorrow, we will try to get 700-800 and then put pressure on the Lankans and get those 20 wickets," he said.
Sri Lanka managed just two wickets after a hard day's toil but Sehwag believes his bowling colleagues can overcome the lack of life on the track and bowl his side to victory.