“The Championship is something that is different for him. He knows that as well,” Matos added.
“He has big talent, big potential, and we want to help him reach the level he wants.
“Then of course in the end of the season he’ll return [to Brentford]. We hope that is a perfect marriage for everyone and we can see all the best of Gustavo in this short time.”
Swansea have been searching for a winger throughout the January transfer window and had shown interest in Crystal Palace’s Jesurun Rak-Sakyi.
Nunes will provide competition for fellow Brazilian Ronald, Eom Jisung and Zeidane Inoussa, though the latter is facing a spell on the sidelines due to a stress fracture in his back.
Manuel Benson also remains at Swansea for the moment, though the Welsh side are looking to cut short his season-long loan from Burnley.
Swansea could also offload centre-back Ricardo Santos this month.
Reading came close to signing Santos last week, but there are now other clubs interested in securing the former Bolton captain’s services.
