India must make a crucial call on the fitness of star pace bowler Jasprit Bumrah for the fourth test against England at Old Trafford.
England can clinch the series with a victory in Manchester but they have top order questions to resolve, while Ben Stokes and Ravindra Jadeja will be looking to repeat their third test exploits.
AFP Sport looks at three talking points ahead of the first day of the test on Wednesday:
INDIA WEIGH UP BUMRAH DECISION
Trailing 2-1 in the five-match series after their painful 22-run loss at Lord's, India cannot afford another defeat if they are to win a test trip to England for the first time since 2007.
That perilous position has increased the pressure to make the right decision on the fitness of Bumrah.
India coach Gautam Gambhir made it clear at the start of the series that Bumrah would only be available for three matches due to a nagging back injury.
Bumrah, 31, played in the first and third tests against England, with India losing both matches, and missed the second game, which the tourists won.
If India opt to use the world's top ranked test bowler in Manchester, it would likely rule him out of a potential series decider in the fifth test.
"We know we have got him for one of the last two tests. It's pretty obvious that the series is on the line now in Manchester so there will be a leaning towards playing him," Gambhir's assistant Ryan ten Doeschate said.
The need to play Bumrah at Old Trafford has been heightened by injuries to India allrounder Nitish Kumar Reddy and seamer Arshdeep Singh.
ENGLAND'S BRITTLE TOP ORDER
England may be within touching distance of winning the series, but questions about their fragile top order remain unsolved.
Polarising opener Zak Crawley could only muster scores of 18 and 22 at Lord's.
Ollie Pope, filling the No 3 spot, reached 44 in the first innings but perished for just four in the second, while Crawley's opening partner Ben Duckett was dismissed for 23 and 12.
England must decide whether to keep faith with Crawley, whose international career has been filled with highs and lows.
Scores of 267 against Pakistan and 189 against Australia showcased Crawley's ability, but the 27-year-old's frustrating habit of surrendering his wicket cheaply has led to calls for a change at the top of the line-up.
However, England have backed Crawley and Duckett to the hilt, and captain Stokes said: "They complement each other. Left-hand, right-hand.
"One is a giant, one is not. It is very hard for bowlers to settle in."
JADEJA V STOKES
After England's Stokes rose to the occasion at Lord's and Jadeja nearly delivered a match-winning innings for India, the allrounders will carry hefty expectations in Manchester.
Stokes led by example in England's third test triumph, scoring 77 runs in two innings, taking five wickets and producing a vital run-out of Rishabh Pant.
Significantly, Stokes was able to push his body through 44 overs, including spells of 9.2 and 10 overs on the dramatic final day.
Now 34, that was the most he has bowled in over six years after being plagued by injuries.
"It was an incredible effort to be able to do that, but that's just how he's built, I guess. He's just desperate to be the man and make things happen," England batsman Joe Root said.
Age was no barrier for the 36-year-old Jadeja either as he kept India in the Lord's test until the last moments.
Now an elder statesman of the team after the test retirements of Virat Kohli and Rohit Sharma, Jadeja's gritty 61 not out from 181 balls took the tourists within a whisker of their 193-run target.
He also scored 72 in the first innings and made 89 and 69 in the second test at Edgbaston.
"I always felt he has the ability to take pressure. With so much of experience, he normally comes with something that the team needs in any challenging conditions. Really, really valuable to the team," India batting coach Sitanshu Kotak said.