The 38-year-old has been interacting with players and coaches of the team ahead of the massive showdown against the European heavyweights.
Muntari is among a tall list of star-studded former stars who have thronged the team's hotel in Doha to offer support to the team.
Muntari, who is on the verge of announcing his retirement from football, was a poster boy during his peak days with the Black Stars.
The former AC and Inter Milan star scored in Ghana's controversial penalty shootout defeat to Uruguay in 2010.
However, he was sacked from Ghana's camp four years later after he physically assaulted former Black Stars management committee member Moses Armah.
Ghana will take on Portugal on Thursday night at the 974 stadium in Doha.