Kevin Thomson admitted that his fellow Hibernian team-mates had let down manager Terry Butcher in their 2-0 defeat at St Mirren.
Early goals from Kenny McLean and Paul McGowan - the first after just 15 seconds - handed the Buddies a vital three points.
Both sides remain just above the relegation zone and the midfielder said: "We never got out of the blocks.
"When you are in the position we are in and give two goals of a start to any team, it will be an uphill battle.
"I'm confident we will be okay come the end of the season but if we keep putting in performances like that then we're going to be in bother.
"I'm just a player and I work hard every day. It's up to the manager to pinpoint what's missing. A few of the boys have let him down and it's time for big characters and big chests.
"We need to stick them out and get three points against Hearts on Sunday. If you can't get motivated for a derby then you shouldn't be playing for Hibs as far as I'm concerned."