A Covid outbreak in the England camp, just two days out from the first ODI against Pakistan, has led to England naming an emergency 18-man squad, featuring a host of names who have been on the fringes in recent times, for various reasons. Here's a run-down on some of the players who will be back in England colours this week.

Ben Stokes

If in doubt, throw the ball to Stokes. England's returning hero had been expected to miss the entire one-day leg of the summer as he continued his recuperation from a badly broken finger at the IPL, with a view to returning for the first Test against India in August. However, after a run of Blast fixtures for Durham - his availability for that had been hastened by another Covid outbreak at Chester-le-Street - he's now been plucked out of his first red-ball game for the county in three years, having taken figures of 3 for 55 in the first innings against Warwickshire.

Zak Crawley

Graham Thorpe, England's assistant coach, recently claimed that the onset of the Hundred might help England's struggling red-ball players to forget their troubles against New Zealand and just get back to enjoying themselves. It seems that Zak Crawley will get a chance to play "see-ball-hit-ball" sooner than that, after his maiden call-up to England's white-ball ranks. His pedigree as a batter is in no doubt - and Pakistan in particular know what he can do after his career-best 267 in last summer's Test series. But since that knock, he's made nine single-figure scores in 12 innings, and continued his rough run of red-ball form with a duck against a rampant James Anderson during Kent's collapse at Old Trafford on Monday.

Ben Duckett

A stalwart of Nottinghamshire's Blast triumph in 2020, Duckett sealed the spoils in the final against Surrey, reaching his fifty off the final ball of their run-chase in a rain-reduced clash at Edgbaston, and atoning in the process for a notable near-miss in the 2019 semi-final against Worcestershire. His star has been back in the ascendancy in recent times - he also made an unbeaten 177 in the Championship earlier this season - but, aside from a one-off T20I appearance against Pakistan in the lead-up to the 2019 World Cup, he's been out of favour at England level since the tour of India and Bangladesh in 2016-17. Despite playing in all three formats, he's never yet played an international fixture in England.

Saqib Mahmood

A huge opportunity for Mahmood to restate his England claims after his fringe role in the bio-secure summer of 2020. After making his debut on the T20I tour of New Zealand in 2019 (another campaign that had an air of a B team about it) Mahmood bowled with pace and economy in a one-off appearance in Johannesburg, before stepping up for the ODIs against Ireland and the T20Is against Pakistan last August. After four wickets in the first two of those fixtures, he went wicketless for the remainder, and was not called up this winter. However, he made his mark in grand style this summer, with a matchwinning five-for in Lancashire's classic Roses victory at Old Trafford in May.

Matt Parkinson

#FreeParky was the cry this winter, as England's legspinner toiled in the nets in futile fashion throughout England's tours of Sri Lanka and India, never getting close to a call-up in any format. Part of the reason, one suspected, was the rough treatment that England's white-ball batters meted out on India's Kuldeep Yadav, a left-arm wristspinner who is similarly renowned for a lack of pace through the air. But this, surely, will be Parkinson's chance to make his point, and add to his tally of two ODIs and two T20Is, the most recent of which came in South Africa in February 2020, shortly before the Covid outbreak. More recently he shot to viral fame after producing a replica of Shane Warne's Ball of the Century, to dismiss Northamptonshire's Adam Rossington in the County Championship.

Danny Briggs

It's not quite a coming-in-from-the-cold to rival Joe Denly's 384-match break between England appearances in 2018, but should Danny Briggs feature at any stage against Pakistan, it'll cap a similarly extraordinary return to the fray. The last of his eight England appearances was at Hobart in January 2014, at the fag end of that abject Ashes tour, when Stuart Broad was still England's T20I skipper, and when England were still two World Cup humiliations away from instigating their white-ball revolution - Stephen Parry (remember him?) would be England's reserve left-arm spinner for the World T20 in Bangladesh later that year. His solitary ODI cap, meanwhile, came against Pakistan at Dubai in February 2012, where he bowled perfectly serviceably as it happens, claiming 2 for 39 in ten overs to help set up a four-wicket win.

John Simpson

One of the outstanding glovemen on the county circuit, John Simpson's first-class career average, at a shade under 32, has kept him out of the Test discussion over the years, but now, at the age of 32, he's got a remarkable shot at a maiden England cap, as the only specialist keeper in England's 18-man squad, even if the likes of Ben Duckett and Phil Salt (broken finger notwithstanding) are capable of taking up the role. In keeping with Middlesex's batting form this summer, Simpson hasn't had an outstanding run of form in the Blast, with 116 runs at 14.50 all told. However, more than half of those came in one glorious knock - 62 from 31 balls against Hampshire at Radlett, to set up a thrilling three-wicket win.

Brydon Carse

South Africa-born but now a stalwart at Durham, Brydon Carse's muscular seam bowling, with regular 90mph speeds, had been attracting the attention of the England selectors prior to the Covid outbreak, in particular on his maiden Lions tour of Australia in February 2020, when he claimed first-innings figures of 3 for 50 in their landmark victory in the unofficial Test at Melbourne. He put the wind up the County Champions Essex with eight wickets in Durham's thrilling early-season tussle at Chelmsford, including a second-innings five-for after bowling them out for 96 first-time out, and has teamed up well with Stokes in the Blast, including against Birmingham in June, where his figures of 3 for 30 helped seal a 22-run win.

David Payne

Left-arm seam has been all the vogue this summer - with David Willey and Sam Curran claiming 22 wickets across formats in the white-ball series against Sri Lanka. But with Reece Topley injured and Tymal Mills limited to T20 outings, that angle of attack now resides in the eternally overlooked hands of David Payne, the man whose final over at Lord's in 2015 secured Gloucestershire their first piece of silverware in 11 years, with victory over Surrey in the Royal London Cup. At the age of 30, Payne was entitled to think his chance had gone, but he's a proven performer on the big stage when his chance comes - earlier this season he proved utterly unplayable when Sky borrowed Middlesex's feed to broadcast their Championship clash at Lord's, finding oodles of pad-hastling swing to scalp a career-best 11 for 87.

Andrew Miller is UK editor of ESPNcricinfo. @miller_cricket