The Hornets released a statement on Tuesday afternoon announcing that Chalobah, 22, suffered the injury during a training session last week, which forced the midfielder to miss Watford’s 2-1 away win over Swansea on Saturday.
A club statement read: “Midfielder Nathaniel Chalobah will soon undergo surgery on a knee injury he suffered in training last week, Watford FC confirms.”
Watford’s Performance Director Gavin Benjafield added: “Whilst we can’t put an exact timeline on his recovery, we are expecting to see him re-integrating into the squad well before the New Year.”
The injury will be a huge blow for Chalobah, who has started all five of Watford’s Premier League matches this season before missing the game against Swansea at the weekend.
Chalobah, who joined Watford from Chelsea in the summer, was also named for the first time in Gareth Southgate’s England squad that faced Malta and Slovakia in the World Cup qualifiers.