Manchester United scouts were present to watch William Carvalho impress for Sporting Lisbon over the weekend, reports Portuguese newspaper O Jogo.
It has been widely reported that David Moyes sees the arrival of Juan Mata from Chelsea as the first of many major additions and is continuing to use a wide scouting network to highlight targets.
With Manchester United struggling to reach the top four in the Premier League, Moyes is ready to spend more money between now and the end of the January transfer window.
One of those targets may well be Carvalho, who has been scouted an number of times by officials from Old Trafford; the latest of which was at the weekend.
Sporting Lisbon took on Penafiel away from home, winning 3-1 with Carvalho playing the full 90 minutes.
The 21-year-old reportedly has a release clause of €45m - the same Manchester United paid for Mata - but it is unlikely Moyes will have to go that high to convince the Portuguese outfit to sell.
However, after growing significantly in stature over the last 18 months, it will undoubtedly take a bid of some significance to convince Sporting to sell their prized asset half way through the season.