The midfielder landed awkwardly in the Baggies' New Year's Day clash with Everton and scans have revealed a fracture will sideline the 27-year-old until March
The midfielder landed awkwardly towards the end of the defeat at home to Everton on New Year's Day and is likely to be ruled out until mid-March.
Brunt's injury is part of a huge setback for Roy Hodgson after the West Brom boss already lost midfield duo Zoltan Gera, who has been ruled out for the season after undergoing knee surgery, and Youssouf Mulumbu, who is currently suffering from a groin strain.
Hodgson is also without the services of star striker Shane Long, who is likely to be sidelined for at least a fortnight after having an injection to ease a persistent back problem.
Long told the Express and Star: "I had an injection yesterday to speed things up but it's very tender at the moment. I'm not training.
"Hopefully it's only going to take a week or two and it's no more serious than that.
"The injection is designed to kill the pain so I can start on my rehab. I'm going to try to aim to be fit for the Norwich game, but that might be a bit too soon."