United lead Arsenal, Liverpool and Chelsea in race to sign teenage wonderkids.
Benfica starlets Joao Filipe and Joao Virginia are on trial at Manchester United, according to Sky Sports.
It was reported last month that Arsenal, Liverpool and Chelsea were also chasing the 15-year-old duo.
However, United appear to be in pole position to land the youngsters, having got them to Carrington for training.
Winger Filipe has been dubbed the “the next Cristiano Ronaldo”, while goalkeeper Virginia is regarded as one of the finest stoppers of his generation.
Benfica are keen to keep hold of the players, but, because they are under the age of 16, they have not been able to sign them to long-term contracts yet.
United have had mixed success with Portuguese players in the past.
Ronaldo signed for just over £12m and was sold for £80m after scoring 117 goals in six seasons at Old Trafford.
Fellow wideman Nani arrived for a fee in the region of £25m seven years ago. His form has been very much up and down.
United paid over £7m for Bebe in August 2010. He has yet to start a Premier League game.