Last season's champions are without a victory in their previous four matches, which has resulted in them slipping down to ninth in the standings.
However, the Brazilian full-back has claimed that the players have not changed the way that they prepare for games, but he has conceded that their confidence has taken a knock.
"We have been working in the same way. I think we have been unlucky some games, maybe that is why, since you lose one game you lose a bit of confidence," he told reporters.
"I think we will work the same way and you just have to have a bit of luck some games to try and win and get the confidence back."
Rafael recently returned to action following a muscular injury.