There had been concern among Celtic fans that they have yet to add to their squad while last season’s title rivals Heart of Midlothian have made 10 signings and third-placed Rangers have made five.
“We’ve a number of players we’re looking at,” O’Neill added. “We have offers in for players at the same time.
“Hopefully in the not too distant future, in the next couple of weeks, we will have some really decent players at the football to add to the decent players we already have at the football club.
“We are absolutely trying to improve the squad and that will be necessary.”
Having started his senior career with Lusitania in the Portuguese District League, Duran moved on to Estrela Amadora but returned to his previous club to help them win promotion to Liga 3 before joining Portimonense in Liga 2.
Overall, he made 48 appearances, 33 of them starts for Qarabag, scoring 15 goals and providing 10 assists last season.
