Coach Gambhir under pressure as India aim for back-to-back T20 triumphs
India, led by Suryakumar Yadav, will begin their campaign against the United States at Mumbai's Wankhede Stadium on Saturday.
It will round off the opening day of the tournament's 10th edition, which has been marred by a chaotic build-up.
Bangladesh last month refused to play in India, citing security concerns, and were kicked out to be replaced by Scotland.
This week the Pakistan government followed up by barring its team from playing against India in Group A on February 15 in Colombo as a protest at Bangladesh's treatment.
The boycott has robbed the group stage of the biggest rivalry and money-spinning spectacle, but leaves India in pole position to top the group.
Pakistan should also progress to the Super Eights in second place, barring a slip-up against the Netherlands, Namibia or the USA, who make up the five-team group.
Top-ranked India reinforced their credentials as tournament favourites with a recent 4-1 win over New Zealand -- their ninth successive T20 bilateral series triumph.
But home defeats in other formats have put Gambhir's high-profile job on the line.
India were beaten 2-0 by South Africa in a Test series last year and New Zealand won an ODI series 2-1.
Gambhir, 44, replaced Rahul Dravid as coach after the T20 World Cup triumph in 2024 and has lost 10 out of 19 Tests.
Swashbuckling Sharma
Indian media suggested the former batsman and World Cup-winner may lose his job if India fail in the 20-team tournament.
"He should stay away from social media till the World Cup and focus on the team," India batsman Ajinkya Rahane told website cricbuzz.
It will be India's first T20 World Cup since the retirements of then captain Rohit Sharma and Virat Kohli following the final victory in Barbados in 2024.
India first won the title under Mahendra Singh Dhoni in Johannesburg in 2007 but will have to defy history to win again, with no team having previously gone back-to-back.
Abhishek Sharma has replaced Rohit in the role of fearless opener, with the swashbuckling batsman scoring at a punishing strike rate of more than 194.
The 25-year-old left-hander is in form. He smashed India's second fastest 50, off 14 balls, against New Zealand.
Captain Suryakumar ended a batting slump with three half-centuries in the same series while Ishan Kishan's comeback has added muscle to the batting order.
Batting great Sunil Gavaskar told broadcaster JioStar that India were full of confidence.
"Even if there is a small stumble, this team knows it can recover, regroup, and continue marching towards victory," said the former India captain.
The bowling attack, led by Jasprit Bumrah, has new talent in the shape of medium-pacer Harshit Rana.
Bumrah, Rana and Arshdeep Singh form the seam attack, with Hardik Pandya and Shivam Dube as the all-rounders.
"It's a luxury that we have a handful of bowlers that can bowl in every situation," bowling coach Morne Morkel said.
"Part of the thinking ... was to look at different sorts of combinations. We don't want teams to have set plans against us."
Spinner Washington Sundar and batsman Tilak Varma are recovering from injury, but both are expected to be fit.