Despite a lack of exposure at Test level, Patchell played a starring role in Wales' opening-round win over Scotland, with regular 10s Dan Biggar and Rhys Priestland both sidelined by injury.
It was Patchell's first Six Nations outing and just his sixth Wales appearance overall, and England coach Jones has warned the Scarlets back that he faces an altogether different challenge at Twickenham.
"The pressure on him is going be enormous. It's whether he has the bottle to handle it," Jones said.
"We'll find out on Saturday.
"He hasn't played much Test rugby at all. He is going to have [Chris] Robshaw at him, [Owen] Farrell at him, [Danny] Care at him - all guys that have played a lot of Test rugby.
"Wales have to get the ball wide and Patchell hasn't played much Test match rugby. He's a young guy, he's inexperienced and is their third-choice 10.
"He's got to get the ball wide and that's going to be a big job. It will be different to playing against Scotland.
"Scotland couldn't cope with the expectation and now he's got to cope with the expectation of playing well.
"Patchell will have to find guys around him to help because he'll be under some heat."
Despite having only a six-day turnaround from beating Italy in Rome on Sunday, Jones opted to make just two changes to his starting XV, with Danny Care replacing the injured Ben Youngs and Jonathan Joseph coming in for Ben Te'o.
On the Joseph decision, Jones said: "It's just my gut feeling with Joseph. I feel he will start the game well against Wales. Jonathan's got great experience, he's fast, a great defensive player.
"We were very happy with Te'o last week, but it's also his second game back and, in my experience with players in their second game back from a long injury, it's always the most difficult game."
Wales' win against Scotland came despite a mounting injury list, and Jones recognised Warren Gatland's side will have a different mindset.
"Wales played really well against Scotland but it's going to be different on Saturday - they had no expectation on them last Saturday but this week they come full of expectation," he said.
"Everyone has been telling them how well they played. Warren Gatland's been talking a lot this week. He's confident. They're confident."