Arsenal watched Porto striker Andre Silva in Champions League action against Juventus in midweek, sources close to the North London club have told ESPN FC.
Portugal international Silva, who has a €60 million release clause in his contract, is regarded as one of the best young players in Europe and Arsenal have made regular checks on him this season.
Representatives were in attendance at the round-of-16 first leg match at the Estadio do Dragao, which the Italian side won 2-0.
Silva, 21, has scored 18 goals in all competitions this season, including four in the group stages of the Champions League, and is a regular in the Portugal team.
Arsenal are looking at possible striking targets for next season as doubts continue to surround the long-term future of Alexis Sanchez.
Porto are reluctant to lose Silva, but financial problems mean they are bracing themselves for offers for their prize asset in the summer.