Colombian James Rodriguez is being lined up by Manchester United as a potential replacement for Nani.

Nani is unhappy with his contract situation and has publicly stated he could leave old Trafford. Sir Alex Ferguson has targeted FC Porto's Rodriguez as Nani's perfect substitute, according to the Daily Mirror.

The 20-year-old has also previously stated his preference to move the English Premier League and particularly Manchester United although his club Porto do rate him at a steep 25 million pounds ($39 million).

United have been monitoring Rodriguez, nicknamed the South American Cristiano Ronaldo, for over a year now with several scouts observing the player last season with Porto and it is understood there were United scouts watching him play for his country as well this month. United face competition from German giants Bayern Munich, who are also keen on the winger. Rodriguez is a player with immense potential and talent and is considered by many in South America to be the heir apparent to Carlos Valderama.

Nani is understood to be furious at the lack of contact from United over his contract, while he represents Portugal at Euro 2012. Nani reportedly wants to earn around 120,000 pounds a week ($188,000). However, United are not willing to offer the Portuguese that kind of money. The winger has two years remaining on his current deal, but is hoping for a new one.

It is believed the Nani camp feels the 25-year-old is being forced out after contracts talks stalled. The arrival of Shinji Kagawa and with Ashley Young and Antonio Valencia doing well, Nani could very well find himself looking for a new club in the summer. Inter Milan are reportedly monitoring developments and could make a move if the player becomes available.