The 51-year-old took over the Nou Camp reins from Tito Vilanova last summer on a two-year deal, and has guided the club to the Champions League quarter-finals, the Copa del Rey final and - following Sunday's thrilling 4-3 Clasico victory - within one point of Atletico Madrid and Real Madrid at the top of La Liga.
His future had nevertheless been a topic for debate, but president Josep Maria Bartomeu stated on Tuesday morning that the Argentinian would honour his contract and Martino later reaffirmed that commitment himself at his pre-match press conference.
"I always respect my contracts," he said, quoted on www.fcbarcelona.cat.
The reigning champions got themselves firmly back in the title frame with an amazing triumph at the Bernabeu, fired by a Lionel Messi hat-trick, but Martino has since urged his players to put that win aside and focus on the remaining nine league games of the season.
"It is important for us to be in the right frame of mind for this run-in to the end of the season, and we are still competing on all three fronts and finding our form, so it's all positive," he said.
"We have to make the most of what we achieved at the weekend, because it has put us back in contention for the league title."
Martino has named the same 18-man squad which travelled to the Spanish capital, with the exception of Cristian Tello's inclusion in place of the rested Xavi.
That means still no place for midfielder Ibrahim Afellay or defender Martin Montoya, or injury victims Carles Puyol, Isaac Cuenca and Jonathan dos Santos, for the visit of Luis Enrique's Celta.
Martino added of Wednesday's game: "I am not worried about the team playing without the required intensity.
"We have gone through a difficult period but have managed to get back into the title race, so I don't doubt that they'll have the right attitude.
"We want to play our very best football and keep performing as well as we did at the weekend.
"A lack of concentration, and not maintaining our level of play and intensity, would put our potential for winning titles at risk."
The match - Barca's 1,000th league game at the Nou Camp - will see former Blaugrana midfielder Luis Enrique return to the stadium he graced for eight years before retiring in 2004.
The visitors will be without injured on-loan Barca midfielder Rafinha and overlooked forward Welliton for the trip to Catalonia.
Luis Enrique, who coached Barca B from 2008 to 2011, said at his pre-match press conference: "Ten years ago I retired as a player and it will be the first time I return to the Nou Camp (as an opponent), a city and a place that I consider most special.
"I had everything that one expects as a player, then as a coach," the 43-year-old said.
"I'll be going back to where my family is and it will be very special. I have always been treated more than good, but I will not be thinking about that.
"I will focus on the game, trying to hurt Barca and on the things we can control."
Luis Enrique acknowledged that his team would have their work cut out against Martino's men - particularly in trying to stifle the threat of Messi.
"Impossible," he said on the prospect of trying to keep the prolific Argentina forward quiet.
"A player who is able to dribble past three players in three metres? How do you defend against that?"
He added: "We are a team not used to playing every three days.
"(But) we have nothing to lose it is a big boost to the players to play at the Nou Camp. I do not see why we should be afraid. We must be bold, daring, direct, courageous... and defend as a team."