 Complete the following phrase:  On 31 August 2017, he was sold to Chelsea for a reported fee of 28 million plus bonuses. He signed a four-year deal at Stamford Bridge. The transfer was completed minutes before the transfer window shut on deadline day. Zappacosta made his debut for Chelsea on 9 September as a substitute replacing Victor Moses in the 74th minute of a 21 away win against Leicester City. He made his Champions League debut and scored his first goal for Chelsea on 12 September 2017, in a 60 home win against Qarabağ FK. With this goal, Zappacosta became the 100th Italian player to score a goal in the Champions League. His first Premier League goal came from outside the box in a 50 home win against Stoke City on 30 December 2017. At the end of the season he was an unused substitute as Chelsea beat Manchester United in the 