India have a three-pronged pace attack for the tournament, featuring Jasprit Bumrah, Bhuvneshwar Kumar and Mohammed Shami, while all-rounders Hardik Pandya and Vijay Shankar offer supporting options. However, with the three frontline pacemen likely to feature in the XI, India lack a back-up option should injury strike one of the three.
"I feel Indian team lacks one more quality fast bowler," Gambhir said. "Bumrah, Shami and Bhuvi need more support. You may argue that India has two fast bowling all-rounders in Hardik and Vijay Shankar, but I am not convinced."
Gambhir, however, endorsed Bumrah, saying he will be India's X-factor in the tournament. Bumrah is the top-ranked bowler in the MRF Tyres ICC ODI Bowler Rankings and is lethal, both as a containing and a wicket-taking option. Bumrah is also potent in the closing stages of the innings, where he is exceedingly hard to put away. Those attributes were visible during the recently-concluded IPL final, where Bumrah gave away just eight runs in his last two overs, including five in the penultimate over of a nail-biting chase.
"The wickets are going to be very flat and it's going to be hot," Gambhir said. "So how Jasprit Bumrah bowls will decide where India reaches, because it's going to be a high-scoring World Cup."
But as an attack overall, Gambhir picked Australia's as the most potent in the tournament. "They have the most well-rounded bowling attack in the tournament," he said. "With Mitchell Starc, Pat Cummins, David Warner and Steve Smith coming back, they're probably the side to beat. In any ICC tournament, if you beat Australia, you're right up there because they know how to play big matches."
Gambhir also praised the present World Cup format, saying that it eliminates the luck factor. "This will be a well-contested tournament as all the teams play each other," he said. "This format will give us the real world champion, and I think ICC should stick to this format for all future World Cups."