Martino's men are now three points behind arch rivals Real Madrid at the top of the table after their 3-1 loss at Anoeta last Saturday.
The defeat marked Barca's second in their last four Liga matches following a surprising 3-2 home reverse against Valencia on February 1.
"The team is very self-critical," Martino said. "Both the players and the coaching staff, and that's why I have complete confidence in a good reaction."
Barca's clash with struggling Almeria comes just a few hours after Real and fellow title rivals Atletico Madrid meet in a crucial derby at Vicente Calderon.
"If we do our job and win, any of the three results in the derby can be favourable for us," the Argentinian added.
"The league title is still in our hands but we need to win all our matches and if we play well, we'll have a better chance.
"What matters right now is that we've got to March with a good chance in the three competitions."
