Manchester City are reportedly ahead of Manchester United in the race to sign highly-rated Croatian duo Sime Vrsaljko and Mateo Kovacic from Dinamo Zagreb.
The teenage pair have been attracting plenty of interest of late, with Bayern Munich and Chelsea also said to be monitoring their progress closely.
According to the Daily Mail, City are the frontrunners to secure a January deal for both Vrsaljko and Kovacic, and would have to part with as much as £25 million to bring them to the Etihad Stadium.
United, meanwhile, have taken a particular interest in Kovacic, and the 17-year-old midfielder has been frequently linked with a move to Old Trafford.
Sir Alex Ferguson is said to be keen on Kovacic, who has been compared to the likes of David Silva and Lionel Messi by the Croatian press.
Kovacic is regarded as one of the hottest prospects to ever emerge in Croatia, and was Dinamo's youngest ever captain when he was awarded the armband in August.
Meanwhile, 19-year-old Vrsaljko is a versatile full-back and would provide competition for Patrice Evra and the Da Silva twins at Old Trafford.