Manchester United are reportedly sending representatives to run the rule over highly-rated Dinamo Zagreb pair Mateo Kovacic and Mario Situm.
According to various reports in Spain, the Barclays Premier League champions will have scouts at the Santiago Bernabeu to monitor the teenage duo as Zagreb take on Real Madrid in the Champions League.
Kovacic has been linked with United for a number of months and Sir Alex Ferguson is alleged to have had aides keeping tabs on the 17-year-old midfielder for some time.
Meanwhile, Situm - it has been claimed - has been brought to the attention of the United boss via his scouting network in eastern Europe, which has borne fruit in the past.
Situm, 19, has scored five times in 12 senior appearances and, should he join United, would add to a stable full of young forward talent at Old Trafford.
Elsewhere, Rio Ferdinand has been left out of United's Champions League squad to face Benfica on Wednesday.
The 32-year-old defender has been required to rest ahed of the weekend's clash with Chelsea.