After a rollercoaster season that has seen the club reach the finals of both the Copa del Rey and the Europa League, Athletic Bilbao remain swamped in transfer speculation with the latest reports claiming that Manchester United will step up their bid to recruit Javi Martinez in the coming weeks.
However, sources suggest that the reigning Premier League champions will face stern competition from Barcelona.
The Catalan side may lose Pep Guardiola at the end of the current campaign but are already looking for ways to improve their side as they attempt to reclaim the La Liga title that they conceded to Real Madrid this season.
With club captain Carles Puyol now at the tender age of 34, Barça are understood to be looking at Martinez as a possible replacement for the stalwart, moulding him from his current position of defensive midfielder to centre-back.
United have their own agendas however and following the financial and, as a result, squad growth at rivals Manchester City, are understandably hoping to draft in reinforcements this summer.
As of yet, any inquiries regarding the availability of Martinez have been outlasted but the standout season that Bilbao have had will undoubtedly be hard for manager Marcelo Bielsa to endure again.
Oscar de Marcos, Iker Muniain and Fernando Llorente are also being linked with moves away from Bilbao.
Despite being only 23 years-old Martinez has emerged a key part of the Athletic Bilbao starting XI, making a massive 50 appearances for the side this campaign.
Vicente del Bosque has been one person to pay attention to this kind of form and has handed the anchorman seven caps for the Spanish national squad since he earned his first cap in 2010.
Should Martinez depart San Mamés at the end of the campaign, he would be expected to warrant a price-tag of around £22m and is bound to ignite a bidding war this summer regarding his signature.