Jason Roy describes his ability to open Test batting as the "great unknown" as England consider promoting Surrey's limited overs specialist for the Ashes this summer.

Roy is contention to partner county team-mate Rory Burns at the top of the order when the series begins at Edgbaston on August 1, with Keaton Jennings' place under most threat.

The 28-year-old has been a star of England's one-day team and could make his Test debut against Ireland in July in an audition for the summer's main event against Australia.

Surrey's director of cricket Alec Stewart is confident he would thrive, insisting "he's a good hitter of the ball and can defend well too", but Roy refuses to make any bold predictions for whether his one-day success against the new ball will transfer.

"It's the great unknown really. I don't know. My technique has shown to be pretty good against fast bowling early on. It's got a lot better and I've progressed a lot in my career over the last two years," Roy said.

"Who knows? It's difficult to say because I've never been part of the Test team or even the squad or the training. I don't really know what the days are about.

"But if given then opportunity then let's hope I can. I'd probably just bat how I bat with a little bit of difference because it's a different gameplan.

If that comeback date eludes him, then the one-off Test against Ireland at Lord's could be his first red-ball outing of the season with the World Cup dominating the early part of the summer. Roy admits he will welcome the change in pace.

"It's always good going from T20 – and even T10 this winter – into the longer format because I'm under less pressure to score at 10 an over," he said.

"It's quite nice to be able to bat, watch the ball and hit the ball. Be relaxed about it rather than score a million runs per over.

"Red-ball cricket can be a little bit relaxing! Although I might have a different opinion when I'm spending a second day in the field."

Roy will continue to open the batting for the sport's top ranked one-day team when they compete in the World Cup on home soil.

England drew their recent series with the West Indies 2-2 but Roy insists they should not be discouraged, instead pointing to the freakish brilliance of Chris Gayle, who struck 38 sixes in the four matches.

"It was a case of a one-man team out there. He obliterated a lot of the bowling, which was actually great to watch in a weird way. As a batsman, I'm allowed to say that!" Roy said.

"It was a strange series, but we're still high in confidence and know we can only get better. It's not like we've stalled."