Saints assistant coach Alan Dickens says the substitution of Alex Corbisiero during Saturday’s 29-6 win against Wasps was ‘precautionary’.
The England prop was forced off after just 27 minutes at Franklin’s Gardens, with Ethan Waller thrust into the action.
Corbisiero headed to the bench and applied ice to what Dickens described as ‘a lower leg injury’.
And Saints are remaining hopeful the 26-year-old, who missed three months of this season with a shoulder injury, will be fit to face London Irish at the Gardens on Friday.
“It was precautionary,” said Dickens. “He’ll recover, get checked over and hopefully he’ll be okay.
“It was a lower leg injury and he’s just a bit tight.”
Corbisiero was released by England earlier in the week, with Joe Marler and Mako Vunipola the looseheads in the squad for the Six Nations win in Wales.
And Dickens, speaking immediately after Saints’ win against Wasps, said: “It (whether he goes back to the England camp) depends on what happens when he’s assessed tomorrow morning.
“It depends on the discussion Jim (Mallinder) has with Stuart Lancaster and the one Matt Lee (Saints’ physio) has with their physio. Then we go from there.”