Some Bristol Rovers players are not dealing with the increased levels of expectation this season, according to boss Darrell Clarke.
Rovers fought back from 2-0 down to level against Oldham on Tuesday, only to lose to a goal two minutes from time.
"One or two are fighting the game," Clarke, 39, told BBC Radio Bristol.
"They have to change that mentality if they want to further their own careers and take this football club forward."
Rovers, who finished seventh last season following promotion from League Two under Clarke in 2015-16, have lost two of their last three League One games after a run of four straight wins in all competitions.
They looked like they had secured a point against the Latics after scoring twice in two minutes, through Rory Gaffney and Ryan Sweeney, to equalise with five minutes to go.
But their hopes were dashed when they conceded the winner three minutes later.
"One or two players are struggling with the higher expectation level this season," Clarke said.
"The levels are higher and rightly so because we finished seventh last season - I'm watching very carefully who in the group wants to really go on and achieve.
"I've asked my players 'what do you want to be? Do you want to be a top-six player or stay in the bottom half of League One or drop into League Two?'
"The lads have got to take it on board and believe in themselves a bit more because we've got some good players."