Scott Brown says he was left shocked after being dropped as first-choice goalkeeper at Cheltenham Town.
The 26-year-old has held the number one jersey since 2008 but the arrival of England U21 keeper Jack Butland, on loan from Birmingham, has seen him fall out of favour with boss Mark Yates.
"I was playing well at the time and it came as a shock to be left out," he told BBC Gloucestershire.
"You've just got to get your head down and take it from there."
Brown was ever-present during last season's League Two campaign and started this term in the same way.
But the arrival of 18-year-old Butland on a short-term loan deal last month meant that Brown has had to settle for a place on the bench and in the reserve team.
He continued: "There's only one place in the team and sometimes there's only one place in the 16.
"In every interview I was reading it said I was doing well so it was a strange one.
"It's a lot easier to take if you're left out and not doing well, you can understand it. But when you are doing well it's quite difficult to take and difficult to get your head round.
"The Crawley [reserve] game was a good game - we had a lot of first-team players out there.
"But going down to Bournemouth it was like an under 18s game so I didn't feel I got much out of that one."
With Butland away on international duty, Brown will reclaim his place in the side for the Robins' trip to Wycombe in the Johnstone's Paint trophy on Tuesday.
"I don't feel like I've got anything to prove to anyone - everyone knows what I can do," he added.
"I'll keep working hard in training and hopefully when my chance comes I'll show that I'm still sharp."