Australia’s Tim Paine is a doubt for the Boxing Day Test against England. The wicketkeeper has not travelled to Melbourne with the rest of Steve Smith’s squad for personal reasons.

A Cricket Australia statement explained an update will be issued in due course. The 33-year-old Tasmanian was a surprise selection for the Ashes ahead of Peter Nevill and Matt Wade. But he has been a success in front and behind the stumps as Australia opened up an unassailable 3-0 lead.

Reports in Australia indicated Paine had flown to Hobart, the Tasmania capital, after his father-in-law suffered a stroke. A replacement has not been called up, with a decision on whether Paine will play expected to be taken on Saturday.

Should he be unavailable, the selectors could recall Peter Handscomb, who was dropped for the third Test in Perth, or promote the opener Cameron Bancroft, who has kept wicket for Western Australia this year.

A CA statement read: “Tim Paine has not travelled with the squad to Melbourne due to personal reasons. An update on his travel plans will be provided in due course.”

Bancroft has signed to play for Somerset next season. The 25-year-old, who was on the receiving end of a playful head-butt from England’s Jonny Bairstow in a Perth nightclub, has played all three Tests, scoring an unbeaten 82 on his debut in Brisbane.

Bancroft, who plays for Western Australia and Perth Scorchers, has 11 centuries in 69 first-class appearances. He is being lined up to feature in four-day and 50-over cricket but not the NatWest T20 Blast.

“I’m really excited to be joining a county with so much potential,” he said. “There’s a long history of Australian’s doing well at Taunton, so hopefully I can add my name to that list. I’ve heard a lot of good things about Somerset from Justin Langer and it’s clear that they are a team heading in the right direction.”

The Somerset director of cricket, Andy Hurry, said: “After a thorough process, designed to ensure that we secure the best fit for our County Championship and Royal London One-Day Cup needs, I am delighted we have signed Cameron.

“He has come very highly recommended and will fit seamlessly into our environment. Cameron has the appetite and the temperament for scoring big hundreds. He really values the price of his wicket, is mentally tough and highly driven to succeed.”