The African champions must first beat Qatar's Al Sadd in their quarter-final at the weekend before launching an attempted ambush of Barca in Yokohama on December 15.
But Ghana defender Harrison Afful, who scored a thumping left-foot rocket to win the CAF Champions League for Esperance last month, said the team feared no one.
"Nothing is impossible. I keep on watching my goal over and over again on my computer," said the full-back, recalling his screamer against Wydad Casablanca.
"I can hardly recognise myself because I'm not used to scoring goals. I'm more of a provider.
"I never get tired of watching my team-mates congratulate me and hearing the Tunisian commentator go wild," he told fifa.com.
Al Sadd are likely to provide stubborn opposition in the quarter-finals but Afful, who was left out of Ghana's World Cup squad last year, believes Esperance could go far in Japan.
"We want to go to Japan and put in some good performances," said the 25-year-old, whose goal made Esperance kings of Africa for a second time, 17 years on from their first triumph.
"It won't be easy for us, but with the ability we've got, I can tell you, we're capable of going a long way in this competition."
Barcelona fly to Japan straight after a top-of-the-table 'Clasico' showdown with bitter rivals Real Madrid at the weekend but are still favourites to win the seven-team Club World Cup.
The Catalan giants, winners in 2009 in Abu Dhabi and beaten finalists in 2006 in Japan, and Brazilian side Santos, join the competition at the semi-finals stage next week.
