Big picture: Can Sri Lanka record the big win they need to have a chance of qualifying?
By the time this match rolls around, both teams could be out. Pakistan are out of contention already, following their big loss to South Africa on Tuesday. Sri Lanka are hanging by a thread after their last-over win against Bangladesh on Monday. If India beat New Zealand on Thursday, they will be out of Sri Lanka's reach, as they India will have won three matches, which Sri Lanka cannot do.
In any case, this is both Sri Lanka and Pakistan's opportunity to finish a campaign strongly. Pakistan are winless as yet in this competition, though rain denied them a near-certain victory over England. Sri Lanka batted poorly in the match against Bangladesh, but were bailed out by their captain in the final over. They will, if nothing else, want to put a stronger stamp on this tournament, which they have essentially co-hosted.
The problem areas for both teams overlap. Pakistan are over-reliant on Sidra Amin with the bat, and have tended to crumble around her. Sri Lanka are not quite as reliant on Chamari Athapaththu as they used to be, but they are yet to put in a dominant batting performance so far. Hasini Perera hit her first international fifty against Bangladesh, but the likes of Vishmi Gunaratne, Harshitha Samarawickrama and Kavisha Dilhari will have hoped to have had better tournaments.
Form guide
Sri Lanka WLLLL (last five completed ODIs, most recent first)
Pakistan LLLLW
In the spotlight: Chamari Athapaththu and Sidra Amin
Chamari Athapaththu will be 36 in February. Unless stars align in extremely fortuitous fashion, Sri Lanka will play their last match of this World Cup on Friday. There is always the chance that Athapaththu will play the next ODI World Cup as well, at age 39. There are certainly no signs that she is slowing down. But realistically, this could be her final ODI World Cup game. She is without a doubt the first woman in Sri Lanka's cricketing pantheon. If this is her last major game in this format, she deserves a strong finish.
Just as an illustration of how far back Pakistan's batting is from the world leaders, consider this. Alyssa Healy, the top runscorer for this tournament, has hit 294 runs in four innings. Pakistan's top run-scorer Sidra Amin has hit 138 runs in five innings. Amin and Pakistan have had consistently challenging conditions in Colombo to deal with, of course, but still, there is both a fragility and a stodginess to this top order, which prevents them from even competing in many matches. If they are to impose themselves on the next World Cup, Pakistan need to develop more batters like Amin.
Team news
Pakistan might search for ways to strengthen their batting order. Could Eyman Fatima or Sadaf Shamas make it back into the XI as they search for better combinations?
Pakistan (possible): 1 Omaima Sohail, 2 Muneeba Ali, 3 Sidra Amin, 4 Aliya Riaz, 5 Natalia Pervaiz, Sidra Nawaz (wk), 7 Fatima Sana (capt), 8 Eyman Fatima/Rameen Shamim, 9 Diana Baig, 10 Nashra Sandhu, 10 Sadia Iqbal.
Sri Lanka will likely keep their XI from the win over Bangladesh. Seamer Malki Madara was economical in that match, and will likely keep her spot.
Sri Lanka (probable): 1 Vishmi Gunaratne, 2 Chamari Athapaththu (capt), 3 Hasini Perera, 4 Harshitha Samarawickrama, 5 Kavisha Dilhari, 6 Nilakshika Silva, 7 Anushka Sanjeewani (wk), 8 Sugandika Kumari, 9 Malki Madara, 10, Inoka Ranaweera, 11 Udeshika Prabodhani.
Pitch and conditions: Can the rain stop, please?
The northeast monsoon shows no signs of easing in Colombo. Expect there to be swing and seam, owing to the rain around. There will also likely be significant turn, so long as the balls aren't too wet. This is all presuming the rain will allow any cricket to be played at all.
Stats and trivia
In 19 World Cup innings, Athapaththu averages 37.61 - just slightly better than her overall stats. Her World Cup bowling average of 30.00 is substantially better than her overall average of 40.12.
Sidra Amin tops Pakistan's run-scorers' chart this year, with 656 ODI runs at 59.63. Their next-highest run-getter, Muneeba Ali, has hit 402 at 30.92.
In 33 ODIs between the two sides, Pakistan have won 11 and Sri Lanka 22.
Quotes
"We've seen how the games have tended to go here. There's been help for the pacers as well. We've studied the wicket carefully and are preparing to adjust our game according to the conditions. There's quite a bit of swing for the fast bowlers, and for the spinners, there's also good turn."
Sri Lanka batter Harshitha Samarawickrama on conditions at Khettarama at the moment
"I've learned quite a lot. This was a huge event - the World Cup - and unfortunately, we couldn't perform as well as we wanted to. But there's so much we've learned from it, and we'll go back home and work hard on those areas.It's been quite difficult because many of our matches were affected by rain."
Pakistan spinner Sadia Iqbal on Pakistan's takeaways from a rainy Colombo campaign