#4 Krzysztof Piatek to AC Milan (£30.9m)
The man meant to be Gonzalo Higuain's replacement at Milan has hit the ground running, scoring twice as they shocked Napoli to progress to the Coppa Italia semi-finals.
Piatek spent barely half a season at Genoa, whom he joined from Cracovia last summer. He scored 13 goals for them from 19 appearances, attracting the interest of several clubs across Europe.
With Chelsea stepping up their pursuit of Higuain, Milan quickly needed to bring in offensive cover for him, and Piatek was available on the cheap. £30.9m in the current market is a great deal for a player with the potential of Piatek.
The 23-year-old has a wide range of abilities. He's excellent in the air, and thrives in finding spaces inside the penalty box. With Milan having brilliant playmakers like Calhanoglu and Suso, Piatek will benefit from the chances they create for him.
He still has only 2 caps for Poland, scoring his first goal for them against Portugal in October. He's naturally viewed by many as his country's long-term successor for Robert Lewandowski.