5. Cristiano Ronaldo
Cristiano Ronaldo is by far the most talked about individual going into this game due to his history with Manchester United. After a record-breaking move to Real Madrid back in 2009, this will be the first time Ronaldo faces his old club and old manager, Sir Alex Ferguson, and if he is allowed to play, or finds his top form, he will be in with a good chance of winning. Ronaldo has scored 182 goals in 179 games for Real Madrid since joining Los Blancosand is a serious threat to Manchester Uniteds chances of progressing through to the next phase. In short, he must be stopped. Madrids number seven is one of the strongest threats to Manchester United and could easily cut through their defence and score if the likes of Rafael and Nemanja Vidic give him half a chance. The 28-year-old, known for his world class free-kicks is a threat from all areas of the field and if United do give Madrid a free-kick in a dangerous area, they could live to regret it.