Les Girondins have lost their last four league games, with the doom and gloom lifted by an impressive two-leg victory over Dynamo Kiev in the last 32 of the Europa League.
On Thursday they visit Portuguese giants Benfica in the first leg of their last-16 clash, and midfielder Sertic insists confidence within the side remains high.
He told www.girondins.com: "We know they are a big team. It does not scare us. We expect a big game. Mentally, we need to react. This is not a league game, we must react quickly to forget those four defeats in a row in the league.
"In the Europa League we have managed to surpass our league performances. Why not do it again against Benfica? Kiev was a very big team. We're ready."
Bordeaux have reason to be optimistic for their visit to the Estadio da Luz given they are unbeaten in six European games and have lost only once in their five away matches in the competition this season.
However, Benfica's record at home is even more impressive. Since the UEFA Cup became the Europa League in 2009, the Lisbon side have won 11 of their 12 home matches, with a draw against Marseille three seasons ago the only blemish.
Assessing Bordeaux's opponents, Sertic said: "They are very technical. They play a game a little like Spanish sides, where they pass the ball a lot.
"Their players are generally quite small in size but with a very big striker in Oscar Cardozo. We will manage this. It should be an interesting result for the second leg at home."
Benfica are duelling with Porto for the Liga title, with the Lisbon side currently ahead by two points, but winger Eduardo Salvio insists that will not distract them from their European objective.
He said on the club's Facebook page: "Now we're thinking about the next game, with Bordeaux, but we know that we have nine rounds remaining in the championship and we will play, as always, with respect for the opponent and thinking game by game.
"We face a very strong opponent and with high quality, they have good players. We will try to impose our game and leave with a good result in our own stadium."