Dawid Malan, Mark Stoneman and Toby Roland-Jones will all be considered for possible Test debuts against South Africa next week during what Trevor Bayliss has described as the toughest selection meeting of his two years as England head coach.

Bayliss and his fellow selectors, James Whitaker, Mick Newell and Angus Fraser, convene Friday and have much to ponder before Thursday’s first Investec Test at Lord’s and Joe Root’s first outing as captain since taking over from Alastair Cook in February.

Though an injury-hit bowling attack that has now seen Jake Ball ruled out with a knee issue represents one headache, Bayliss and Co will likely spend more time debating the batting side of things – the top three of which appeared to have been solved on last winter’s tour of India when Haseeb Hameed and Keaton Jennings both shone opening alongside Cook.

Hameed has struggled this summer however – the 20-year-old averages just 15.9 for Lancashire in the County Championship – and with Root keen to drop a spot to No4 given the additional leadership responsibilities, Stoneman comes into contention after impressing for Surrey since his winter switch from Durham. Sam Robson of Middlesex, who failed to convince during seven Tests in 2014 but averages 76 this year, is also in the mix.

The No5 position could also be up for discussion too if Jonny Bairstow, the wicketkeeper, moves down the order below the all-rounder Ben Stokes. Gary Ballance – scorer of 815 runs for Yorkshire this season – and Middlesex’s Dawid Malan, who struck a 44-ball 78 on his Twenty20 international debut last Sunday, are the two seemingly under consideration here.

“In the two years I’ve been here it will be the toughest selection meeting that I’ve had,” said Bayliss of a squad which will officially be named at 9am on Saturday. “It’s a good problem to have when you’re struggling to know which guys to put in.”

On the 30-year-old Stoneman, who has made three centuries for Surrey this season, an all-too familiar issue for Bayliss has emerged, with the Australian admitting: “To be honest, I haven’t seen him play. He’s done some hard yards up at Durham. But he’s not the only one who’s being discussed. Robson has been scoring some runs. I liked the look of Malan.”

A recall for Ballance, who is captaining the Lions in their ongoing three-day match against South Africa at New Road and has been championed by his county team-mate Root, behind the scenes, would represent a third stab at Test cricket after being dropped last winter – something Bayliss appears lukewarm about.

He said: “It’s great to see him scoring runs. One thing Gary’s always had in his favour is he’s mentally tough – that’s why he’s been able to come back and score a lot for Yorkshire. There’s no reason why he can’t make a success of it but somewhere along the line the selection panel will have to decide whether it’s time to look at someone new.”

Ball’s injury – a knee strain, with a two-week recovery period that sees him miss Nottinghamshire’s Royal London final against Surrey on Saturday – is offset by the news that Stuart Broad has reported no ill-effects from bowling in the nets with a heel problem, although a second planned session was scuppered by rain at Trent Bridge on Thursday.

But with Chris Woakes out with a side-strain, Stokes having undergone an injection to ease a knee problem and Jimmy Anderson on the comeback trail from a groin strain, it is a worry when Mark Wood is suddenly the seamer in the rudest health. Roland-Jones, the uncapped Middlesex right-armer, could therefore come into the squad at his home ground.

Spin-wise, Moeen Ali will be naturally be first choice, albeit likely to drop back down the order in a move that sees Jos Buttler, who finished the Test series in India as specialist batsman at No7, pushed out. The question will then be whether the uncapped Mason Crane or Adil Rashid will be included as slow-bowling cover for Moeen in the squad.

South Africa, meanwhile, are expecting captain Faf du Plessis to join their squad in time for the first Test after his wife, Imari, gave birth to their first child on Monday. The tourists reached 58 for one from 20 overs on a rain and light-affected first day against the Lions that saw the Sussex left-armer, George Garton, remove Dean Elgar in the morning.