The last time India toured Sri Lanka for a bilateral ODI series, they put in place what became a key component of their 50-overs strategy for the best part of the next two years. It was in Colombo, in the fifth ODI of a series that India won 5-0, that Kuldeep Yadav and Yuzvendra Chahal first bowled together.
They came together because India had struggled for middle-overs wickets during the 2017 Champions Trophy, and the wristspin partnership went a long way towards solving that issue: between that tournament and the 2019 World Cup, only Afghanistan among Full-Member teams had a better collective bowling average in the second powerplay (overs 11-40) than India's 32.98.
In that period between ICC events, Yadav (87 wickets at 21.74) and Chahal (66 at 25.68) were the top two wicket-takers in all ODI cricket. They featured in tandem in each of India's first six matches at the 2019 World Cup, but that sixth game revealed the cracks in the strategy.
The pitch at Edgbaston was flat, and one of the square boundaries was significantly shorter than the other. In those conditions, England's marauding top order took full toll of Yadav and Chahal, who took just the one wicket between them while going for 160 in their 20 overs. India's chase of 338 never really got going, with their lack of lower-order batting seemingly forcing the top order to minimise risk and play for net run-rate.
That was the last time India picked both Yadav and Chahal in an ODI XI. Since then, they have left one on the bench and partnered the other with a spin-bowling allrounder, usually Ravindra Jadeja. In this new world order, both the wristspinners have struggled to match their earlier impact. Since the World Cup, Yadav averages 58.41 in 12 ODIs, and Chahal 37.12 in five. Both have economy rates north of six an over. Both have suffered demotions in India's contracts hierarchy.
It is at this juncture in their careers that Yadav and Chahal return to the R Premadasa Stadium, the venue where their partnership took root. They return as senior members of a side missing a number of regulars, but neither begins this three-match ODI series as a certain starter.
When India last played an ODI, against England in Pune, neither was part of their attack. Chahal was benched for the entire series, and Yadav, who had been hit for eight sixes in the second ODI, was dropped for the decider, with India picking just the one spinner - allrounder Krunal Pandya - and four frontline quicks.
On this Sri Lanka tour, Yadav and Chahal will compete for spin-bowling spots with legspinner Rahul Chahar, offspinner K Gowtham, left-arm spinner Pandya and mystery spinner Varun Chakravarthy, who, it would seem, might only be in contention for the T20Is that follow the ODI series. Of those four, Pandya and Gowtham are allrounders to varying degrees.
Whichever combination they pick in Colombo, India would hope they arrest a worrying overall slide in their middle-overs displays. Since the World Cup, the team's collective bowling average in this phase is an unflattering 43.75...
… and their economy rate a worrying 6.05. While the sample sizes are small, given the lack of cricket that's been played since the onset of Covid-19, no other team has done as poorly on this front.
There are mitigating factors, of course. India's schedule has pitted them against some of the world's best hitting sides since the World Cup, with all their ODIs in this period coming against Australia (six matches), England (three), New Zealand (three) and West Indies (six). India's first-choice bowlers have often been unavailable or returning from injury.
Most significantly, India's new-ball bowlers have struggled, averaging an eye-watering 150.42 in the first ten overs of ODIs. This has had an obvious knock-on effect on the middle-overs bowlers, who have often had to begin their spells against set batters on extremely flat pitches. In the last ODI Yadav featured in, for instance, Ben Stokes was able to slog-sweep him with abandon even when he was hitting against the turn and dragging the ball from well outside off stump.
Given all that, this series against a Sri Lanka side that's beset by on- and off-field strife, on pitches that should offer some help to the spinners, couldn't have come at a better time for Yadav and Chahal. But with all the other contenders breathing down their necks, they might need to serve up a reminder of all their old magic.

Karthik Krishnaswamy is a senior sub-editor at ESPNcricinfo