Neil Lennon expects Celtic to make a fourth summer signing "in the next few days", while admitting midfielder Jose Cifuentes is on the club's radar.
Lennon refused to elaborate on the unnamed target after the 5-2 aggregate Champions League win over FK Sarajevo.
It has been reported that former Leicester City right-back Danny Simpson, 32, would be joining on trial.
Lennon told BBC Scotland before the 2-1 win that Ecuadorian youth cap Cifuentes had "come up on the radar".
"It's a player who we know very little about, so that's all I can say on that one," he said of the America de Quito midfielder, who has also been linked with Manchester City.
Speaking after goals by Ryan Christie and Callum McGregor at Parkhead helped set up a second qualifying round tie with Estonian champions Nomme Kalju, Lennon stressed that a right-back "is a priority".
Centre-back Kristoffer Ajer deputised in that position in both legs against Sarajevo after the summer departures of Mikael Lustig and Christian Gamboa.
"I think we'll maybe have something in the next few days," Lennon said. Asked if it would be a right-back, he replied: "Maybe. It might be a right winger, maybe a centre-forward. There are a number of positions - midfield, one or two other areas in an attacking sense as well."
Lennon was "very satisfied with the performance and result" against the champions of Bosnia-Herzegovina, but warned such games are "fraught with risk and danger" as he looked forward to next Wednesday's first leg against Nomme Kalju in Glasgow.