Zaheer Khan was a doubt for India heading into Sunday's fifth one-day international against England here at Headingley.
The fast bowler twisted his ankle while batting during Thursday's three-wicket defeat at Old Trafford, a result that left India 3-1 down and needing wins in all the remaining three games to claim the seven-match series.
Left-armer Khan missed practice at Headingley on Saturday and is now set for a fitness test before play on Sunday.
His absence would be a huge blow on a ground where the often overcast conditions can assist swing bowlers. Back-up pace bowler Munaf Patel has been erratic while Khan's fellow left-armer Rudra Pratap Singh and the experienced Ajit Agarkar have been inconsistent.
"We're monitoring his (Zaheer's) situation," India captain Rahul Dravid told reporters at Headingley on Saturday. "He's been treated by the physio and the physio says there's been improvement.
"We have 24 hours and before the game he'll go through a fitness test. Obviously, we want to give him as much time as possible. The good thing is he had the injury while batting and was able to bowl after that.
"His ankle is fine and if it holds up well it will be great. It was a bit swollen after the game but it's come down drastically in the last 24 hours."
Dravid added that with major Test series against Pakistan and Australia on the horizon, protecting the fitness of Khan, India's man of the series with 18 wickets during their 1-0 Test success against England earlier this season, would be a key concern.
"You obviously want your best bowlers to play when you're two down and need to win the next three. But if he's not fit, he's not fit. There's not going to be an issue on that.
"If the physio and Zaheer feel he's not fit, we're going to play someone else. His management is as important to us for himself and for the team."
One consolation for India during their defeat at Old Trafford was the form of Agarkar who removed four of England's top six on his way to figures of four for 60 in 10 overs.
"Ajit's got some good rhythm," said Dravid. "We knew we needed wickets in that game and he came back well. He bowled well in the early part of the tour and then went away and came back. He too (like Munaf) needed a bit of bowling. He's got that and is okay."