Martino: We have not been consistent
Pressure is starting to build on Martino after Barcelona lost to Real Valladolid on Sunday, a result that saw them drop four points behind La Liga leaders Real Madrid.
That was the club's third loss in their last six league games and means the Calatan giants go into Wednesday's clash with Manchester City in uncharacteristically erratic form.
Barca lead their last-16 UEFA Champions League tie 2-0 after a dominant performance in the first leg at the Etihad Stadium, meaning a place in the quarter-finals is expected.
"I accept that we haven't been consistent," Martino said.
"To play one day against Manchester City (in the first leg) like we did, and then to play the way we did at Real Valladolid, that's wrong. We need consistency if we are to win all three competitions (Champions League, Liga and Copa del Rey).
"It would be possibly dangerous if we get thinking about the 2-0 from the first leg. This is a fresh start. (We will) think of things as 0-0 and go out to win tomorrow's game.
"(Despite the negative headlines), we need to be positive. I certainly wouldn't count us out of the league, we're in a strong position to reach the quarter-finals of the Champions League and we're in the final of the Spanish Cup."
Barca president Josep Maria Bartomeu said on Tuesday that he hopes Martino stays at the club for many years to come.
"Martino has a contract with us until June 2015," Bartomeu told radio station Cadena Ser.
"We would like Martino to remain with us next season. We hope he will remain with us for a long time.
"He is eager to do things well and win."
Barca defender Javier Mascherano, meanwhile, echoed his manager's comments about approaching Wednesday's game on the front foot.
"We need to keep playing the way that we have been playing for all these years," he said.
"The team that has got a result to defend, that's ourselves, but we have to go out and stay faithful to our system. The game is in our hands at the moment and we have a very good chance to get into the quarter-finals.
"We do not want to give them any chance to play in bigger spaces. The right way to do is to try and get the ball for the majority of the game."