Marcus Watson has left London Irish to join Saracens.
The 20-year-old winger has represented England Under-20s and sevens.
"I enjoyed my time at London Irish, but I'm looking forward to the challenge of making an impact at Saracens," he told Sarries' official website.
"I've been impressed by the work ethic at the club, and the way everybody is able to switch on and switch off."
The news comes after trio Steve Borthwick, Neil de Kock and Kelly Brown signed contract extensions with the London club.