On Tuesday, Barca host Arsenal in the return leg of their Champions League quarter-final tie, having drawn the first meeting 2-2 at Emirates Stadium last week after the Gunners hit back from two goals down.
Pep Guardiola's side then travel to the Bernabeu next Saturday to take on arch rivals Real Madrid in 'El Clasico', a match that could go a long way to deciding the destination of the Primera Division title.
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Both clubs are locked on 77 points after 30 rounds, with Madrid currently holding the upper hand due to their superior goal record, but reigning champions Barca boast the slight edge in the head-to-head record after winning the first meeting 1-0 at the Nou Camp.
Looking ahead to the two matches, Abidal said: 'We're playing for the season this week.
'Before the game with Madrid there is an important Champions League match and the best way to go into Saturday's game is by qualifying for the semi-finals.
Massive week: Abidal (right)
'We are the reigning champions of the competition and we must fight hard for this trophy. For me it's the most important game of the season and at home, especially, we cannot slip up.
'We will have more confidence (for the Madrid game) and we will be stronger going into that game if we win.'
Abidal, who has only recently returned from a lengthy spell on the sidelines with a thigh injury, was also asked about the prospect of facing Arsenal's Theo Walcott on Tuesday.
Danger man: Barcelona will be wary of Walcott following his blinding second-half spell in the tie's first leg
The pacy Walcott made a big difference after coming off the bench in the first leg and Gunners fans will be hoping he can make a big impact at the Nou Camp.
Abidal told Marca: 'Football is a sport that is played with the ball. It may be really good to run 100 metres in a little over 10 seconds, but the aim is to get to the goal.
'We'll wait for him there and we'll see what he can do with the ball. Let's see if he can get past four defenders.'
Barca will be missing at least three key players for the Arsenal game, with centre-backs Carles Puyol and Gerard Pique suspended and striker Zlatan Ibrahimovic injured.
Pique and Ibrahimovic are also fitness doubts for the Madrid match, but Spain midfielder Andres Iniesta exercised today with a personal trainer and Guardiola will be hoping he will be available soon.