Pakistan heads into its series finale against England at The Oval wondering if an extra bowler can help it square the four-match series at 2-2. After losing the first Test at Lord's by 75 runs, England has bounced back with victories by 330 runs and 141 runs at Old Trafford and Edgbaston respectively. A recurring scene throughout the series has been the sight of Pakistan's four-man attack tiring badly during prolonged spells in the field. The tourists lack an all-rounder of the caliber of England rising star Chris Woakes, with out-of-form opening batsman Mohammad Hafeez, who made two and nought at Edgbaston, still barred from bowling his off-spinners because of an illegal action. Pakistan needs to take 20 wickets at The Oval, where the fourth Test starts Thursday, if it is to draw level. It didn't manage it at Edgbaston last week where England declared its second innings on 445 for six. At Edgbaston, Pakistan replaced struggling opener Shan Masood with Sami Aslam and saw the 20-year-old left-hander make impressive scores of 82 and 70. Now it could give a Test debut in south London to Iftikhar Ahmed, a top-order batsman who also bowls off-spin. "He bowls off-spin and decently, England has a lot of left handers so he does give us an option as a fifth bowler if he comes in," Pakistan coach Mickey Arthur told reporters at The Oval Tuesday. "But we have to be dead certain he can come into our top six and get runs, because we'll be asking for runs first and bowling second." Arthur said playing five bowlers was also under consideration. "It's certainly one of the options, but whoever comes in somebody has got to bat in the middle order, which makes it a particularly long tail," the South African explained. "It's one that we've thought about and one I lay in bed thinking about it last night. "That's a very positive option because we've got to get 20 wickets in this Test match. We've got to work through that one." Yasir Shah took stunning match figures of 10 for 141 at Lord's, including six first-innings wickets. It was asking a lot for Shah to maintain that form on English pitches. That, allied to better England batting, has seen Shah come back down to earth with a combined returned of four for 502 in the last two Tests. "I'm hoping we can get runs on board here, it turns a bit and there's a bit of bounce — and that's a leg-spinner's best friend," said Arthur. Pakistan could also do with some runs from Younis Khan. He has had a lean series with just 122 runs in six innings. "He's so professional on and off the field," Arthur said. "Put it this way, he's giving himself the best chance to perform." England could go top of the world Test rankings for the first time since 2012 if it wins at The Oval and India does not emerge victorious in both of the remaining matches of its series away to the West Indies. It must decide whether to give a home debut to leg-spinner Adil Rashid. England also has a few question marks against its top-order batting beyond captain Alastair Cook and Joe Root. Alex Hales, Cook's opening partner, has yet to make a Test century and number four James Vince is still searching for a first fifty at this level. Hales, however, did share his maiden century opening stand with Cook at Edgbaston as the pair erased a first-innings deficit of 103 runs.