4. Robert Lewandowski
He set the world alight with his performances in the Euros this Summer, scoring the first goal of the tournament. His performances as well for Borussia Dortmund have highlighted the attention of many top European clubs, most notably RVP rivals Juventus. His final game for Dortmund (one which featured Uniteds new sigining Kagawa) last season saw him score a hat-trick against arch nemesis Bayern Munich, cementing his place as a top striker. At just 23, Lewandowski has at least another ten years at the top. He would set United back a fair fee, but to get a top quality ten years could be worth it. Though with Dortmund already selling Kagawa to United, the chances of them getting rid of their other best player could be very limited.