5) Dries Mertens (Napoli)
After a stellar season with Napoli in 2016/17, it comes as somewhat of a surprise that no major club tried to sign Dries Mertens. The Partenopei finished third in Serie A last season but take nothing away from the Belgian forward who lit up the Italian league.
28 goals and 9 assists is what Mertens finished with in the last league campaign. After Gonzalo Higuain was sold to Juventus for a record fee and Arkadiusz Milik tore his ACL on international duty, the burden fell on Mertens to lead the attack.
Standing a little over five-and-a-half feet tall, the 30-year-old Belgian formed a potent partnership with Lorenzo Insigne and Jose Callejon in attack, ably assisted by Napoli veteran Marek Hamsik behind them.
Mertens eventually ended the season with 34 goals in all competitions.