John made his first senior appearance in more than two months after his recovery from an ankle injury.
However it proved a difficult outing as Rovers suffered a 3-0 defeat at Gillingham in the FA Cup.
As a 20-year-old loanee making his first steps in senior football, John admits the game was a major learning experience on what happens when performance levels dip.
But he also says that all of the side can learn from the mistakes of Sunday as they look to shake off their worst performance of the campaign ahead of last night’s Leasing.com Trophy clash with Leicester City U21.
“It wasn't the comeback I thought I'd have but it's a learning curve.
“Not just for me but for everyone really,” John said.
“It shows how there are dips in form and how the game changes in the men's game.
“It's a tough one to take for me personally.
“But I can learn from it and take it in my stride and go again next week.
“That was not the way we play.
“It's not the way we like to play football.
“It just was a bad day at the office.
“We've got Wednesday to put that right and then the weekend too.”
Rovers were given a tough time by Gillingham’s powerful forwards Mikael Mandron and Brandon Hanlan, but John believes he will be better for the experience.
He said: “They're two big physical strikers in this league.
“It's something that personally I will take and look back on and something I can keep using for my experience and keep working on.”
John appears likely to sit out Wednesday’s clash with Leicester U21s to ensure he is available for Saturday’s League One clash with MK Dons at the Keepmoat.
Tom Anderson’s three match suspension does not cover the Leasing.com Trophy while youngster Shane Blaney is pushing for selection.