Buttler missed the Fourth Test defeat at the Kia Oval for the birth of his second daughter, Margot.
Jonny Bairstow kept wicket with Ollie Pope coming into the XI and scoring 81 in the first innings.
Those two are now battling for one place in the side, at No5.
Root said England would “consider that over the coming days”.
“Jos is vice-captain and a senior player,” said Root.
“He is integral to what we are about. I know his output in terms of runs hasn’t been as high as he’d like, but we know what a great player he is and how important he can be in turning a Test match.”
England’s bowling stocks are also stretched, with Jimmy Anderson and Ollie Robinson tired but keen to play.
Craig Overton is set to be available after the nasty bang to the elbow he suffered batting on Monday.
Mark Wood is likely to come into the side, while Sam Curran and second spinner Jack Leach are also options.