The Surrey batsman’s 87 proved invaluable in England’s winning 373 for three against Pakistan in Saturday’s second one-day international.
It provided the foundation for an innings then dominated by Jos Buttler hitting a 50-ball century as England triumphed by 12 runs.
The teams meet again in Bristol today, with Roy fit and firing again after a hamstring injury that was followed by back trouble.
“A few movements didn’t feel quite right, but it was nice to spend time out there and running between the wickets,” Roy said. “The back actually feels way better than it did before, so I should have had the injection earlier.
“It [spasm] feels disgusting. It grabbed on to my sciatic nerve and kind of ran down the back of my left leg and I couldn’t quite straighten it.
“There are absolutely no worries whatsoever at the moment. I’ve had a muscle spasm before, but this was a bit worse. I had the medical staff around me, and they reassured me that kind of issue could resolve very quickly.
“I spent six or seven weeks out with a small hamstring tear, and then to come back and miss a couple more weeks because of my back was extremely frustrating.
“It was so special walking out there on Saturday. The goosebumps were going, and it was a really good feeling.
“It was good to get a score when I am feeling rusty, to be honest. It’s a good sign and shows I am in a pretty good space mentally. “Pressure is pressure, and all you can do is go out there and be the best player you can be and not worry about anything else, to be honest.”
It was a superb start for England, with Jonny Bairstow and Roy taking the home side past 100 without the loss of a wicket but Roy added: “I was absolutely livid with myself when I got out on Saturday, because that is what I have changed the most over the last two-and-a-half years, turning my 60s and 70s into hundreds. I was fuming.”
Buttler, pictured, looks set to get a breather today, with Kent’s Joe Denly potentially replacing him in the line-up, while another switch could see Tom Curran or Mark Wood in for Adil Rashid. And captain Eoin Morgan is poised to break Paul Collingwood’s England record of 197 one-day international appearances when he leads the team out.
The England squad trained in Bristol on Monday, with the dust only just setting on Buttler’s spectacular century.
It was the second-fastest hundred by an England batsmen in one-day internationals, and Roy told Sky Sports: “He is as good as it gets, to be honest. It is not kind of a shock.
“It is getting a bit routine for him to go out and play those innings. He comes in and just blitzes it.
“He is an extreme talent, works hard for it and deserves everything he gets.”