Arsenal and Barcelona target Aymeric Laporte will not leave Athletic Bilbao for less than £30million, according to Basque newspaper El Correo, reports talkSPORT.
The France U21 international has attracted a number of admiring glances in recent months, with scouts from La Liga and the Premier League monitoring his development at San Mames.
Gunners boss Arsene Wenger has been credited with an interest in bringing Laporte to the Emirates Stadium, but will have to meet his release clause to have any chance of luring the 19-year-old to north London.
With question marks surrounding the long-term future of club captain Thomas Vermaelen, Arsenal might need to add another defensive reinforcement, to act as cover for current first-choice centre-back pairing Per Mertesacker and Laurent Koscielny.
Meanwhile, Tata Martino is also in the market for an eventual successor for Barcelona legend Carles Puyol, and has also expressed a desire to bring the talented teenager to Camp Nou.
Ernesto Valverde will be eager to keep Laporte at Bilbao until at least the end of the season, but will be powerless to prevent him from negotiating with other clubs, should they meet his valuation.