The sides will clash for the first time since last year's Asia Cup final, a tense event staged following military conflict between India and Pakistan that nearly escalated into a fully-fledged war between the nuclear-armed neighbours.
The latest meeting comes after Pakistan, who were angered by Bangladesh's removal from the tournament for refusing to play in India over security concerns, threatened to skip the contest before abandoning that plan.
"I expect the game should be played in the spirit that it has always been played since its inception," Pakistan captain Agha told reporters in Colombo on Saturday.
India beat Pakistan three times in the Asia Cup, including in the September 28th final in Dubai, but refused to shake hands with their opponents before or after matches.
"We'll find out tomorrow (if it happens)," Agha said.
Pakistan's boycott threat put at risk one of the sport's most lucrative fixtures, leaving broadcasters fearing millions of dollars would be lost in advertising revenue.
The International Cricket Council (ICC) held a series of negotiations before securing a compromise to ensure the match would go ahead as planned.
"India vs Pakistan is a game of high magnitude... Tomorrow's game is no different," Agha added.
"From our side, before heading into the tournament, we were prepared for all possible scenarios - whether the game would go ahead or not."
Agha said the captains carried much of the pressure.
"It's an added responsibility when you are the captain of your side, and you're representing your country," he said.
"You can't run away from the responsibility. When you're representing your country and captaining a side, there will be pressure. You just need to find a way to deal with that."
With the threat of rain on Sunday looming large, Agha said Pakistan were ready to adapt.
"We cannot control that, but we're ready to make adjustments if the game gets shortened," he said.
Both teams have won their opening two matches of the tournament.