Keighley-born Reed sustained the injury half an hour into the NRL game at AAMI Park in Melbourne after colliding with an advertising board as he attempted to keep the ball in play.
The 24-year-old bravely played on for around 15 minutes despite the suspected dislocation and possible fracture but will now undergo scans to determine the extent of the injury.
Brisbane coach Anthony Griffin told reporters it was the same shoulder Reed has had reconstructed and that the injury was "not good".
It is another major worry for England coach Steve McNamara after Melbourne's Halifax-born stand-off Gareth Widdop suffered a dislocated hip a fortnight ago.
Widdop said this week that he is still hoping to get back before the end of the NRL season to prove his fitness ahead of the World Cup, which gets under way on October 26.
Both Widdop and Reed were certainties to be named in McNamara's squad after playing in the 2011 Four Nations Series.
Reed was out for six weeks earlier in the season with a fractured eye socket.
McNamara, who has met all his NRL-based England players during a three-week trip to Australia, was in Sydney on Friday, taking in his 10th and final match, St George Illwarra's clash with the Roosters, before flying home.