Premier League champions Manchester United and neighbours Manchester City are tracking big money transfers for Porto defenders Eliaquim Mangala and Nicolas Otamendi. According to the Daily Star, both Manchester clubs are having the pair scouted in Portugal. City have used seven different central defensive pairings this season largely because captain Vincent Kompany has been struggling with injury. United's chief executive Ed Woodward has confirmed that the club's transfer priorities on David Moyes' succession as Sir Alex Ferguson's replacement were a central defender and a left back. Argentina international Otamendi, 25, is rated at £25 million by the Star and was named in Alejandro Sabella's latest national squad this week. He has 15 caps for his country so far. Chelsea are also chasing 22-year-old Mangala, capped three times by France and valued by the same report at £40 million. The Star say that David Moyes may even offer out of favour midfielder Anderson as a bargaining counter to land either Otamendi or Mangala in January with Porto thought to be keen on a loan deal for the player they sold to Old Trafford for £17 million six years ago. In other City news, Manuel Pellegrini is stepping up his interest in Germany international midfielder Sami Khedira. The Sunday People/Daily Mirror writes that the 26-year-old could be brought to the Etihad from Real Madrid in a £30 million deal.