Sri Lanka have lost in the first two matches which means there is a high chance of Sri Lanka losing in the third match as well. That is, whether Sri Lanka can save themselves from being whitewashed, it will be understood in the third match. Sri Lanka lost the first match by a narrow margin but Sri Lanka lost the second match by a huge margin of 45 runs. If Sri Lanka plays the third match with the same squad then there will definitely be more chances of defeat in the third match as well.
Sri Lanka have confirmed their series loss with 1 match remaining. I think Sri Lanka went into the field with their best XI from the announced squad for the second match of the 3-match T20 series against New Zealand. But the second match was a bigger loss than the first match. I don't think it is possible to form a better XI from this squad. In the last match of the series, we may be seeing Sri Lanka lose again and Sri Lanka is going to see a series whitewash.
New Zealand's added advantage at home and their great form is definitely a cause for concern for Sri Lanka. Even in terms of T20 rankings, Sri Lanka is a bit of a weak team. Considering their recent form and the field, New Zealand will definitely get extra support for a win and maybe New Zealand will win the match very easily. Sri Lanka will go into the field with the aim of avoiding a shameful whitewash by winning the last match, which is definitely going to be a tough match for Sri Lanka. Although the chances of a change in the Sri Lankan XI are very slim, they may innovate their plans and field two legspinners. In this case, we may see Jeffrey Vandersay in the XI instead of Mathisha Pathirana. On the other hand, it is more likely that New Zealand will see an unchanged XI.