Gordon pulled his groin 10 minutes into Glasgow's 34-20 Celtic League win over Ulster at Hughenden on Saturday.
The Daily Record reports that the extent of Gordon's injury will be revealed today, but it's feared he could struggle to be fit for the autumn Test series against Australia, South Africa and Japan. In Scott Murray's absence, he had been favoured to become Scotland captain.
Gordon's injury took the gloss off a great display from Glasgow, but despite the blow, Hugh Campbell insisted the win couldn't have been more timely. He said: "It was a real confidence boost with the Northampton game just a week away. It was ragged at the start but then the composure came and we were able to take control.
"Dan Parks was immense. He's come back well from a bad game at Swansea. I was also delighted with Sam Pinder at scrum-half - he's throwing his hat into the ring for a cap next month.
"But we can't kid ourselves about the threat Northampton pose. They are former champions and jam-packed with quality players."
Hugh also told today's Herald: "We had to fight hard to beat an Ulster team who were fairly disorganised through changes, injuries and so on, so we've got to keep our feet on the ground. It will be a tough task against Northampton and it's our biggest game of the season so far.
"We can go in with confidence, but we've got to be realistic, too. They will be difficult opponents who were going pretty well in their Premiership early on. They've lost a bit of ground, but we have to come out with the thought that we are playing good rugby, are playing well and can challenge them."