Barcelona have fallen behind Atletico Madrid in the title race but the coach is adamant that they must not think about their fellow contenders if they want to succeed
The Catalans head into the match on the back of a home defeat to Valencia, although they bounced back with a 3-1 win in their midweek Copa del Rey semi-final first leg against Real Sociedad.
Barca now sit second in the three-horse race for the Spanish crown - ahead of Real Madrid on goal difference but behind leaders Atletico Madrid - and Martino has stressed that they must forget about the teams around them and put all their energy into defeating Sevilla.
"The match against Sevilla is probably the most difficult we have left," the Argentine told reporters on Saturday. "It is crucial and will have hugely positive or negative impact on our future.
"We need to not think about [Atletico and Real Madrid] and focus on making ourselves stronger, thinking only about football.
"There's a long way to go in La Liga, still."