Saints boss Jim Mallinder has revealed Kahn Fotuali’i pulled his hamstring in the win over Exeter Chiefs on New Year’s Day.
Fotuali’i was forced off after just 25 minutes, with club captain Lee Dickson coming on to help his team record an important 8-3 Aviva Premiership success at Franklin’s Gardens.
And Saints will now hope the Samoan can make a speedy return to fitness, with big games on the horizon.
A derby date with Leicester Tigers at Welford Road is next up, with Champions Cup clashes against Glasgow Warriors and Scarlets to follow.
But Fotuali’i would appear to be a doubt for some if not all of those games, with Saints likely to have to call on summer signing Tom Kessell to provide back-up for Dickson.
“I think it’s his hamstring,” said Mallinder. “He’s pulled his hamstring.
“We’ll just have to see how he reacts during the week.”