Nacional have not received an official approach from Arsenal for midfielder Ruben Micael.
Portuguese press reports have linked the Gunners with the 22-year-old, who is joint-owned by Nacional and Uniao.
Arsenal, who were also recently said to be keen on Nacional's Nene, have yet to comment on the rumours.
Micael is highly-rated and it is claimed Nacional could be open to offers in the summer.
A statement read: "Right now we are only aware of the rumours in the newspapers."