Graeme Swann baffled with England selection for Oval Test

Former spinner Graeme Swann has been baffled by England selectors' decision to pick Tom Westley over Mark Stoneman for the third Test against South Africa to be played at The Oval beginning Thursday.

Westley will make his Test debut and bat at No.3 in place of Garry Ballance, who was ruled out of the game with a broken finger.

The 28-year-old amassed 478 runs at 53 with two centuries for Essex in the County Championship while Surrey's Stoneman has 761 runs at 59 with three hundreds and a top score of 197.

It is these figures because of which Swann has been left stunned for Stoneman's omission from the crucial third Test of the four-match series against the Proteas.

"The most incredible thing is Mark Stoneman still not being given a chance," cricket.com.au quoted Swann as saying.

"Westley looks a good talent but they must know something I don't know because, why they have gone for him over Stoneman, there must be a reason behind it. His numbers have been immaculate over the last couple of years and I think it is very harsh on him he hasn't been picked in this squad," he added.

The 60-Test veteran however praised Westley, saying that he is a very good player.

The Essex batsman will come in after left-handed opening pair Alastair Cook and Keaton Jennings, with the latter struggling for form after two Tests against the Faf du Plessis-led side.

Jennings has scored just 44 runs in four innings this series including scores of zero in the series.

And Swann believes that England's top order is nowhere near settled.

"There are so many places up for grabs it is ridiculous," Swann said.

You have the opening berth to go alongside Alastair Cook and the No.3 slot because Gary Ballance hasn't really worked out and has now broken his finger. He must be the most vulnerable man in world cricket at the moment," he added.

England won the first Test at Lord's by 211. However, the Proteas made a fantastic comeback beating the Joe Root-led side by 340 runs at Trent Bridge to level the series 1-1.