Henriques, who played four tests, 16 one-day internationals and 24 T20s for Australia, will lead a 14-man Portugal squad at the T20 World Cup Europe Sub-Regional Qualifier C in Finland.
The 39-year-old all-rounder, who was born in Madeira, the birthplace of Portuguese footballer Cristiano Ronaldo, retired from Australian domestic cricket last year.
Portugal face Israel, Germany, Greece and Czech Republic in Group B of the tournament, which runs from August 14-20.
The group winners will advance to a final, with the overall winners progressing to the European regional final alongside Scotland, Jersey and Denmark.
The top two teams from that event will secure places in the global qualifier for the 2028 T20 World Cup in Australia and New Zealand.