The attacking midfielder made the switch from the no.18 shirt he has worn in his first two seasons at the club, taking up a number worn by some of the club’s most iconic stars.
The Spain international joined the Hammers in June 2019, becoming the second most expensive signing in the club’s history.
One of West Ham’s first England internationals, Bill Brown, wore the number eight shirt when the team were promoted to the First Division and reached the FA Cup final for the first time in 1923.
Ronnie Boyce wore the number when his last-minute goal secured the Irons’ first ever FA Cup victory in 1964, in a thrilling 3-2 win over Preston North End.
When the team returned to Wembley in 1975, Graham Paddon wore the shirt in theo FA Cup Final victory over Fulham, while the 1980 final saw the Hammers beat Arsenal with Stuart Pearson in number eight.
Scotland forward Frank McAvennie wore number eight for the celebrated Boys of ‘86 team, scoring 26 goals to help the club to their highest ever league position.
More recently, the likes of Teddy Sheringham, Scott Parker, and Andy Carroll have all sported the jersey during spells at the club.
Now 25-year-old playmaker Fornals takes the number eight shirt from Brazilian winger Felipe Anderson, who recently left the club to rejoin Lazio after three years in claret and blue.
The new Umbro-designed home kit which Fornals will don was launched last week, with members of staff from Barking, Havering and Redbridge University Hospitals NHS Trust given a first look.
This week, the Hammers will continue their run of pre-season friendlies with a game against Reading on Wednesday (July 21) and against Celtic on Saturday (July 23).
Manager David Moyes said he was pleased to be able to get 90 minutes into the legs of several of his senior players after a double-header of friendly matches last Tuesday.
Moyes watched on as his team battled to a goalless draw at Leyton Orient, while another team at Northampton secured a 2-1 victory.