Pandya was hurt as he tried to stop a shot with his foot off his own bowling during the hosts' seven-wicket win over Bangladesh. He missed India's wins over England and New Zealand.
"His procedure after the injury is very positive. Right now, he is not available for tomorrow's match," Rohit told reporters on Wednesday at the Wankhede Stadium.
"Hopefully, we'll get a chance to see him as soon as possible."
Rohit's men have lived up to their billing of favourites for the 50-over showpiece event, winning all six of their round-robin games, and they face Sri Lanka hoping to seal their last-four spot.
Sri Lanka have won two out of six games.
Rohit said the hosts will not hesitate to field three frontline spinners if conditions favour slow bowler.
"All sorts of combinations are possible," Rohit said.
"In this tournament, you've seen that spinners are actually the ones stopping that run flow in the middle overs.
"I'm keeping my options open... Our spinners have got so much skill in these conditions."
Worsening air quality in Mumbai has also been a big talking point during the tournament with England's Joe Root complaining about difficulty in breathing after the team's 229-run loss to South Africa at the Wankhede Stadium.
Rohit, who hails from Mumbai and leads the local Indian Premier League franchise, had earlier posted on social media a picture of the Mumbai haze taken from his flight.
"In an ideal world, you don't want a situation like this," Rohit said.
"I'm pretty sure the concerned people are taking the necessary steps to avoid these kind of situations.
"But obviously, looking at our future generation, your kids, my kids, obviously, it's quite important that they get to live without any fear... we have to look after our future generation."
