Manchester United sent scouts to Portugal in order to watch Eliaquim Mangala in action this week, according to The Guardian.
The 23-year-old was close to joining Manchester City in the January transfer window but a deal fell through because Porto stood firm on their valuation of Mangala.
Now it looks like United are following up their own interest in Mangala having scouted him against Atletico Madrid previously.
City are expected to make a fresh move for Mangala in the summer but David Moyes may well decide that he is the perfect player to bring to Old Trafford in light of Nemanja Vidic (and possibly Rio Ferdinand). If both players leave, United would have to replace at least one.
Mangala is strongly considered to be one of the best defensive prospects in Europe and at 23, he has his entire career ahead of him which would make him a very solid long-term investment.
However, it is unlikely that United would be able to compete with City for wages so if we were to battle them for Mangala, we could find ourselves simply outbid.