Messi's Barca team-mate David Villa ended a barren goal run and gave an emphatic response to a jibe from Mourinho when he scored twice in Saturday's 5-0 La Liga rout of Sevilla.
Argentina forward Messi, who also scored twice, said the champions were not affected by comments from people outside the club.
"You shouldn't attach any importance to what Mourinho says," he told reporters. "He tries to draw us into his game but we have to focus on our work."
Mourinho had sought to defend out of form Real striker Karim Benzema on Friday by turning the focus on Villa's lack of a league goal in more than a month.
"Other teams have great players in the same situation (as Benzema) and nobody is talking about them," said the Portuguese.
Villa, joint top scorer at the 2010 World Cup in South Africa with five goals, helped see off Sevilla by curling in a sublime shot and then racing through to net his second, and Barca's fifth, in the 90th minute.
"If we are winning I am content," the 28-year-old said. "I scored (on Saturday) but next time maybe I'll make a different kind of contribution."
"The player is happy because a born goal-scorer needs goals and he got them," said the coach.
