Mahela Jayawardena as opener
The most obvious thing sri lanka could change is promote jayawardena to the top of the order the numbers support the move as the jayawardena averages a significant percent more as opener than playing in the middle order.The continuous failure of kusal janith and the erratic form of upul tharanga means sri lanka have a big problem at the top of the order, and very little time to find a solution. Bringing in the experience of jayawardena as opener would mean sri lanka would be putting all their eggs in one basket. If all three(mahela,sanga,dilshan) fail at the top, it would leave Mathews and the unreliable juniors to handle the pressure. This is probably the reason the selectors were reluctant to let jayawardena open the batting, but going into the world cup rewards may heavily outweigh the risks.
Tharindu kaushal as a proper spinner
The current spinners sri lanka have tried are sachitra senanayake,rangana hearath,seekuge prasanna,chathuranga de silva and suraj randiv. Barring injury rangana herath will be playing in the world cup. His most likely partner would be sachithra senanayake but with his action under scrutiny there will be doubts if he can return at the top of his game, if not sri lanka should be prepared .Looking at the back up spinners all three of the above mentioned rely on stopping the batsmen scoring rather than relying on flight and spin to get batsmen out.With batsmen continuously finding innovative ways to score runs ,grounds getting smaller, outfields becoming faster the strategy of limiting run scoring is becoming irrelavant.This is where tharindu kaushal can be an asset he is known to spin the ball and rely on flight to get wickets rather than containg the batsmen. His current form against west indies and a strong domestic record suggests he could be a good option as a backup spinner. Sri lanka would be wise to try out the youngster.
Bring back Farvees Maharoof
Before the emergence of thisara perera forgotten man farvees maharoof was the great allrounder the sri lankans were hoping would allow the team greater balance in bowler friendly conditions.While perera has the greater ability,maharoof is a better professional in addtion to his all round capabilities,he has been working hard in domestic and recently played against west indies A.Maharoof has over a hundred ODI wickets and above a thousand runs in 104 ODI.He has represented sri lanka in every age group, surely the team could use his experience in bowling, and his lower order batting ability can be an asset .Considering where the world cup is being played he is a man that should be in the loop. If nothing else this might push thisara perera to improve his allround game.
Left Arm Seam Bowler
In the absence of Lasith malinga sri lankas bowling has been monotonous lately and has been easy for the batsmen to play against.A left arm seamer would add a bit of variety to the attack .There aren’t much promise out there as left arm bowlers the one to look out for is Binura Fernando. The 19 year old stands at 6 foot 6 has a reputation for bowling fast and swinging the ball. He is yet to make his first class debut but was called up to the squad against Pakistan early this year therefore we can assume the selectors have big plans for him .He might be an option worth testing out before the world cup.