Luther Burrell will have an X-ray on his right hand after injuring it in Saints’ 34-6 win against Ospreys on Saturday.
The England centre, who was named in the Elite Player Squad earlier in the week, was forced off during the second half of the match at Franklin’s Gardens.
Will Hooley came on in his place and Saints proceeded to rack up a bonus-point Champions Cup victory, with George North grabbing all four tries.
But Burrell’s injury will be a worry, especially for England, who begin their autumn international campaign with a game against New Zealand on November 8.
“Luther has banged his hand,” said Saints boss Jim Mallinder, who was forced to withdraw Burrell’s centre partner James Wilson after just nine minutes.
“It’s very sore and he’s struggling to grip. He’ll have to go for an X-ray on that.
“He gave it a chance and put some tape on at half-time. Fingers crossed there’s no permanent damage.
“It could be anything - it was a bone in his hand.”