Bruce had been hoping to name Gordon in his starting line-up for Saturday's home game with Wigan, despite a long-standing knee problem that had been hampering the Scotland international's movement for a number of weeks.
The Black Cats boss was intending to cancel a planned operation, but after medical advice suggested surgery should take place as quickly as possible, Gordon went under the surgeon's knife. As a result, the 28-year-old now faces a race to be fit for the start of pre-season training.
We hoped we could nurse Craig through, said Bruce. That was still the hope after the weekend. But we got a specialist to have another look at him, and once that happened, we had to revise the plans.
Once we had another look at his knee, it was apparent that there were problems. He's had a partial tear of one of the tendons and it had to be cleaned up. We had discussions with Craig, but it was pretty obvious that he was struggling.
In more bad news, Fraizer Campbell will undergo a second operation on his knee in London today, a procedure that will rule the striker out of most of next season.
There is, however, the prospect of some brighter developments ahead of the weekend, with Danny Welbeck, Kieran Richardson and Sulley Muntari all rated 50-50 for the game with Wigan. Anton Ferdinand should return to full training within the next 24 hours and be available to face the Latics