Michael Vaughan has questioned whether England have made mistakes in their preparations for the series with Pakistan in the UAE.
England head into their latest challenge in the longest format on the back of Ashes success in the summer, but Vaughan believes that Alastair Cook and his players must raise their levels again in the three-Test series.
A 3-0 defeat to Pakistan in the spin-friendly conditions of the UAE three years ago is still fresh in the memory and Vaughan is unsure whether the tourists are fully prepared for what is to come.
"This is the most difficult by a country mile because of the conditions and because of the inexperience of spin that England have got," the former England captain is quoted as saying by BBC Sport.
"I wonder if England have missed a trick with their preparation.
"I do worry that England haven't had competitive games going into this series in such a challenging place."
Pakistan are likely to be without leg-spinner Yasir Shah, who is currently battling back spasms ahead of Tuesday's first Test.