Julian, who is currently on loan with Turkish side Kasımpaşa S.K., wasn’t involved in the fixture as his national side came from behind to record a 2-1 win.
Lisandro Semedo actually put Cape Verde ahead in the Algarve as he found the net on 39 minutes.
The second half was just one minute old when Guinea struck back through Malado Kaba before they went ahead 20 minutes later through Sambégou Bangoura to claim the win.
Julian has earned five caps since making his debut in the build-up to last summer's Africa Cup of Nations finals, being named in the matchday squad on a further four occasions.
The side will now make preparations to take on Gambia on Tuesday next week.