Jason Roy has been ruled out of England's three-match T20I series against Pakistan after sustaining a left side strain.

Roy picked up the injury this week during the white-ball squad's preparations at Emirates Old Trafford, and had a scan on Wednesday.

He will remain with the England set-up and will undergo rehabilitation work ahead of the Australia white-ball series, which starts next month at The Ageas Bowl.

"Unfortunately he tweaked his side two days ago now and will be ruled out for the three games in order to give him time to prepare for both series against Australia," Eoin Morgan, England's white-ball captain, said.

"At the moment we don't anticipate it being anything serious, but we want to give him every chance to be fit for both series."

England have, at this stage, decided against drafting in any official cover for Roy, with Liam Livingstone, the likeliest batting stand-in, remaining among England's reserve players.

"At the moment, given that we have a lot of flexibility, particularly with our allrounders in Joe Denly and Moeen Ali, and the reserve batters in the squad, at the moment we don't feel a need to pull anybody in for tomorrow," Morgan added.

Roy struggled for form during the ODIs against Ireland, making 25 runs in three innings, and his absence may offer an opportunity for Tom Banton to open the batting alongside Jonny Bairstow, just as he had done in Roy's absence in New Zealand before Christmas, where he played the first of his three T20Is.

Dawid Malan, who scored 103 not out from 51 balls in that New Zealand series, is another man back in contention for a top-order berth, especially in the absence of Jos Buttler due to his Test commitments, and though Morgan said that England had an idea of what their rejigged top three would look like, he said they would not be revealing their plans until the toss.

"Dawid in particular has really put together an early establishment of a career that, every time he's available, he's put himself forward as the next man, simply by weight of runs and the rate at which he scores them," Morgan said.

Banton featured in England's middle order in the recent ODI series against Ireland, and after initially struggling for the appropriate tempo, he made his mark with a maiden international half-century in the third match at the Ageas Bowl.

"[Banton] naturally is a top-order batter, but at a time where we have top-order batters in abundance and actually lack middle-order players, it's sometimes difficult to get him in in the position that is his strength," Morgan added.

"We know what he can achieve at the top of the order, along with a number of other guys who bat in the top five. And so hopefully if he gets a chance he can take it."

England play the first of their three matches against Pakistan on Thursday, with the subsequent two games coming on Sunday and Tuesday, all at Old Trafford.