Sri Lanka captain Kusal Mendis won the toss and elected to field in Thursday's World Cup match against unbeaten hosts India who can seal a semi-final place with victory.
India, the only team yet to lose a match at this World Cup, are unchanged with captain Rohit Sharma happy to bat first on his Wankhede Stadium home ground, where South Africa piled up 399 after being sent in by struggling champions England earlier in the tournament.
"I would have batted first," said Rohit. "It's a good pitch...Under lights, it will be nice for our seamers to bowl.
"It's a great honour to captain India at the World Cup (on a ground) where I've grown up playing.
"As a team, we thrive on getting better. Obviously, it's important for us to not get carried away and it's important to stay balanced."
Sri Lanka made one change from the side that suffered a seven-wicket defeat against Afghanistan, with leg-spinner Dushan Hemantha in for Dhananjaya de Silva.
Mendis's men have lost four of their six games in the 10-team tournament.
"I think batting second is better than batting first. The players have done well in a couple of matches and are giving their best. It's a very important three games (coming up) for us," said Mendis.
Teams
India: Rohit Sharma (capt), Shubman Gill, Virat Kohli, Shreyas Iyer, KL Rahul (wkt), Suryakumar Yadav, Ravindra Jadeja, Kuldeep Yadav, Jasprit Bumrah, Mohammed Shami, Mohammed Siraj
Sri Lanka: Pathum Nissanka, Dimuth Karunaratne, Kusal Mendis (capt/wkt), Sadeera Samarawickrama, Charith Asalanka, Angelo Mathews, Dushan Hemantha, Maheesh Theekshana, Kasun Rajitha, Dushmantha Chameera, Dilshan Madushanka
Umpires: Chris Brown (NZL) and Paul Reiffel (AUS)
TV Umpire: Rod Tucker (AUS)
Match Referee: Jeff Crowe (NZL)
Agence-France Presse