Reports today confirm that the transfer of Mamadou Sarr to Real Sociedad has reached a breakthrough stage after Chelsea gave the green light to the move and reached an agreement with the interested team. While personal terms and contract length are yet to be agreed - it is looking increasingly likely that the Real Sociedad are about to get one of their top transfer targets signed and sealed. Real Sociedad have laid out their intentions, but valuation and timing remain under debate. Chelsea are keeping tabs in case talks collapse or progress slows further. Chelsea continue to be linked with Francisco Fernandes Conceicao, Lamine Camara and Jordan Henderson while Real Sociedad are also rumoured to be tracking Nayef Aguerd. Follow us on Twitter @PlayerSwitchCom and get the latest Real Sociedad transfer news and rumours direct to your feed.