Chris Boyd says the decision to leave Piers Francis and Cobus Reinach out of Saints' squad to face the Dragons on Saturday was 'precautionary'.
Both players suffered injuries during the week, with Francis troubled by a pectoral issue and Reinach struggling with a heel problem.
Reinach was named on the bench to face the Dragons but was withdrawn from the squad, while Francis was not selected in the 23.
And Boyd said: "He (Francis) picked up a little pec niggle from the gym so that's the first injury of that type we've had this year.
"He was withdrawn, and Cobus sustained a foot injury at training on Thursday so we pulled him out this morning.
"Both of them are precautionary really."
George Furbank was forced off after just five minutes against the Dragons after being knocked unconscious while trying to stop centre Jack Dixon in his tracks.
Full-back Furbank was down for some time before eventually walking off the field to be replaced by Andrew Kellaway.
"He had a bit of a sleep on the field there," Boyd said.
"He doesn't seem to be suffering from any symptoms and he didn't have to go through a HIA (head injury assessment) process because he was clearly sleeping, but he seems to be fine."