The 27-year-old was forced to leave the field after feeling the injury during his side's 1-1 draw with Aston Villa last month.
However, the Northern Irishman has insisted the blow is not as severe as first thought and hopes to regain full fitness ahead of the busy Christmas fixture list.
|14/1||West Brom are 14/1 to finish in the top six with Paddy Power|
"It wasn't as bad as we thought at first because it felt like a nasty one when I got it at Villa Park, so in that sense it isn't too serious.
"The problem is that it's happened a couple of times now, so this time I want to make absolutely sure it's right before I come back because it's no use to anybody doing two or three weeks at a time and then getting another injury.
"At least with the international break I won't miss so much football, but once we're back and you start the run towards Christmas the games come at you without a break, so I need to be right for this period coming up."