Dubai - Pakistan
England should be confident after reclaiming the Ashes on home soil this year with a 3-2 win over Australia, but Alastair Cook's charges may also feel some trepidation after their last series against Pakistan in 2012 ended in a 3-0 whitewash.
Spin duo Saeed Ajmal and Abdur Rehman were England's tormentors back then, taking 43 wickets for an average of 15.6 runs, but they are absent this time so Shah and Babar will be Pakistan's main spin threat in the three-test series.
Both are late bloomers.
Shah, 29, made his test debut last year and has since claimed 61 wickets in 10 matches including 24 against Sri Lanka in July. Babar, 36, has 42 wickets in 10 matches following his 2013 bow.
"The way he (Shah) is bowling he's a threat to every team, he's our strength," said Pakistan captain Misbah-ul-Haq, 41.
"To win a test match, a series, you can't just focus on one bowler. Zulfiqar and the fast bowlers will play a key role because of the reverse swing, especially with the new ball."
Younis Khan, Pakistan's all-time third-highest run scorer, will be crucial to the host's batting hopes especially after Azhar Ali was ruled out of the first test due to injury.
Most Pakistan players arrived in the UAE on Wednesday from a one-day series in Zimbabwe. The team opted for just one warm-up match, a sign of confidence about playing in their adopted UAE home where Pakistan remain unbeaten in seven series.
"Any away team these days seem to be the underdogs," England coach Trevor Bayliss told reporters.
"Experience-wise, we've got some young players but players with a lot of ability and skill. There's no reason why we can't play some good cricket and if we play some good cricket we'll be hard to beat."
Joe Root, the world's third-ranked batsman, will be England's main scoring hope after many of the specialist batsmen struggled in the Ashes.
All-rounder Moeen Ali, a handy off-spinner and regular at No.8, seems likely to become Cook's seventh opening partner since Andrew Strauss's retirement in 2012 as the tourists try to instil greater resolve at the top of the order.
"It's always a challenge whenever you play Pakistan; the trial by spin will be tough," said Cook.
Only five England players remain from the 2012 mauling -- batsmen Cook and Ian Bell, plus fast bowlers James Anderson, Stuart Broad and Steve Finn.
All should make the starting XI for the opening test in Abu Dhabi, Finn staking his claim with 4-16 in the final warm-up game against Pakistan A.
On-field temperatures could top 40 degrees Celsius for much of play so England may opt for a six-man attack.
Adil Rashid seems poised for his test debut after the spinner ended a six-year absence from one-day internationals this year, which would likely leave Mark Wood and Ben Stokes, another all-rounder, vying for the final bowling spot.
Dubai will stage the second test from Oct. 22 and Sharjah the third from Nov. 1.