England have Ollie Pope on standby to keep wicket in case Buttler is unable to make a full recovery before the match.

In the absence of Jonny Bairstow, who was dropped from the Test squad, Pope is the reserve wicketkeeper. The 21-year-old has taken the gloves in just five first-class games so far, most recently in February this year when England Lions played against India A.

If Root were to resign, who do you think should replace him?@Ben_Wisden looks at the likely candidates. https://t.co/GTH7d9d0Ml

— Wisden (@WisdenCricket) November 27, 2019

Buttler reportedly complained of back pain while working out in the gym just before training on Thursday.

“Jos has tweaked his back in the gym,” said England captain Joe Root during the pre-match press conference. “We’ll have to find out a little bit more information on that throughout today and tomorrow and see where he’s at.”

Buttler’s exclusion will open up a middle-order spot, which could be filled by Kent right-hander Zak Crawley, the only specialist batsman in the 15-member squad who didn’t feature in the first game. The uncapped Crawley made a century in England’s first warm-up match at Whangarei a couple of weeks ago.