The Reds are now looking anxiously over their shoulder following a 2-1 defeat to the Eagles.
A familiar face returned to haunt them on Merseyside, with Christian Benteke bagging a match-winning brace.
Jurgen Klopp’s side, who still sit third, are now just three points clear of fifth-placed Manchester United having played two games more than their arch-rivals.
"It was stupid from us," Can told the club’s official website.
"But we have got to go again and it is still in our hands. If we win the last four games, we will reach the Champions League. That has to be the target. It has to be."
Liverpool were once again undone by balls into the box against Palace, with deficiencies from crosses and dead-ball situations having been an all-too-familiar theme running through the Reds’ season.
"We should have won this game. Again it was a set piece,” added Can.
“We had worked on them in training, we had trained very well. All the set pieces in training we had done very well.
"But again we concede a goal after a set piece. It was stupid. We are frustrated, disappointed. It is always the same. We controlled the game, I think we didn’t play too bad but then we conceded two goals from two chances…. It’s very disappointing."
Liverpool are next in action against Watford on May 1, when they will be looking to repeat a 6-1 mauling of the Hornets from earlier in the season.