Welbeck signed his first trainee contract in July 2007, and started the 2007–08 season in the under-18 team, but was quickly promoted to the reserve team, making a number of substitute appearances.
Welbeck skrev under på sin første kontrakt i juli 2007 og startede 2007-08-sæsonen i U-18-truppen, men blev hurtigt rykket frem til Reserveholdet, hvor han lavede et antal optrædener, hvor han kom ind som udskifter.