The latest incumbent at three, Moeen Ali, has played six innings there at an average of just 14.50, including a first-ball duck in the first innings and three runs overall in the Galle test.
England coach Trevor Bayliss has suggested Ali could be moved down the order for the second test in Pallekele starting on Wednesday, and named one-day specialist Buttler and Ben Stokes as potential replacements.
"I will bat wherever is required," Buttler told the BBC.
"...You need a good balance of being settled but it shows a good team environment and ethic that people are willing to play wherever is required."
With England's regular test wicketkeeper Jonny Bairstow sidelined with an ankle injury, Ben Foakes stood behind the stumps in preference to Buttler in the first test, scoring an eye-catching century on his debut to lead the visitors to a 211-run win.
All three could play in the second test, but Buttler, who scored 38 and 35 in the first, is focussed on keeping his place by putting runs on the board.
"If Jonny was fit, I wouldn't be the wicketkeeper anyway, so Ben Foakes keeping didn't really bother me," he added.
"In your pride as a wicketkeeper, you want to be good enough to be selected - but I didn't keep as well in the one-day series as I would've liked to and it's quite healthy to see someone like Ben come in."
(Reporting by Hardik Vyas in Bengaluru; editing by John Stonestreet)
