Monreal was first linked with a return to Basque Country in the summer, with the Mirror reporting that Athletic Club were keen on signing the 28-year-old, along with Mikel Arteta.
However, nothing came of the interest, but that has not prevented Los Leones from tracking his availability ahead of a potential January move for the Pamplona-born international.
Monreal has appeared 16 times for the Gunners this term in the league, with a further seven appearances across other competitions. Despite enduring something of a slow start to his career in North London following his transfer from Malaga in January 2013, Monreal is enjoying a consistent run in the first-team this year, but that has not deterred Athletic Club from attempting to make a move for him.
Being born in Pamplona makes Monreal one of few players eligible to turn out for Bilbao through their cantera philosophy, in which only Basque-born players can represent the club. This limits the pool of potential signings that the club can make, and SportWitness, as first reported by the print edition of Marca, have suggested that the club will be willing to offer Monreal a pay-rise and long-term contract to prise him away from the Emirates Stadium.
However, the report indicates that any move they make will be dependant on whether the Gunners strengthen themselves during the January transfer window, and they will potentially hold off on opening negotiations until the summer to make the deal slightly cheaper.
Despite the financial benefits of delaying a deal, Athletic could be rushed into making a deal at the closing stages of the month if their defensive performances do not improve, with the club struggling in mid-table in La Liga, with 10 losses already registered from just 19 games.