Ireland excelled when reaching the Euro 2012 finals but their experience in Poland was a difficult one as they lost to Croatia, Spain and then Italy.
Their start to World Cup qualifying has been mixed - wins over Kazakhstan and Faroe Islands sandwiching a heavy 6-1 defeat to Germany - and some Ireland fans appear to have lost faith with the vastly experienced manager.
However, McCarthy, who took the Republic of Ireland to within a penalty shoot-out of reaching the 2002 World Cup quarter-finals - says Trapattoni is still the man for the job.
"They've done what they had to do [in World Cup qualifying] - they've won the two games that they should have done," McCarthy told Yahoo!-Eurosport.
"In Giovanni Trapattoni they have a guy who gets results.
"He got them to the European Championship finals. They lost to all the teams in it, it wasn't a great championship, but they had the two finalists in their group and Croatia who are a good team.
"The results he is expected to get, he gets them."
Mick McCarthy was speaking to Yahoo!'s 'The Dugout' through its partnership with the League Managers Association