But McManus is defiant that they will not give up the title without a fight.
The skipper said: "We can't let it affect us. We have to get straight back to business and produce a good performance at the weekend against Motherwell.
"Every game is a must-win and we will keep fighting.
"It won't be hard to bounce back. Saturday's game will be tough but they all are at this stage. We certainly believe in ourselves and one another. We will be fine.
"It's a blow because we have not won. Everyone is bitterly disappointed, but you have to drive everyone on."