Costa, 25, has been the outstanding performer in Mallorca's squad this season, evolving from his original profile as a disciplined defensive midfielder into a dynamic box-to-box operator under current head coach Martín Demichelis.
He has scored seven goals — more than doubling his previous best return — and attracted attention from clubs in the Premier League, Serie A and, now, the Gulf.
Mallorca's management is under no illusions about the summer ahead, reports Marca. The club is preparing for Costa's departure and view a sale as necessary to fund their own rebuilding, while also aware that with two years remaining on his contract and his value at its peak, the window to extract maximum value is now.
Al-Rayyan, the Qatari club who count former Real Sociedad forward Rodrigo Moreno and Spain international David García among their squad, moved first through a representative who spoke directly with Ortells. The €25 million asking price was the club's response — a figure that reflects both Costa's market value and the 20 per cent sell-on clause retained by Almería from the deal that originally brought him to Son Moix.
Last summer Mallorca rejected Premier League and Saudi interest after holding firm at a €20 million minimum, with no club meeting that threshold. This year the valuation has risen, and the expectation inside Son Moix is that the fee is achievable given Costa's continued development.
Costa has represented Portugal twice at senior level and is being closely monitored by national team manager Roberto Martínez ahead of the World Cup. His profile as a left-footed all-action midfielder capable of driving forward from deep is seen as an increasingly rare commodity in European football.