Northampton director of rugby Jim Mallinder says that lock Courtney Lawes will be out injured for several weeks.
The 22-year-old is having a scan on his knee but should be available for the Six Nations if selected, with England opening against Scotland on 4 Feb.
Mallinder told BBC Look East: "I think he'll be out for a few weeks. It's not a serious one.
"He was playing really well [so] it's really disappointing for him, but it's not his season over."
England's new interim head coach Stuart Lancaster is set to name the squad for the Six Nations on 11 January.
"We picked Courtney in the back row against Newcastle and he had a really good, solid game," added Mallinder.
"Particularly in the last 20 minutes, he was tackling well, getting around the field and putting in some really good defensive hits.
"We need to look after him and hopefully he'll come back fit and ready to go."
Meanwhile, Saints hope to recall Calum Clark to their squad for the Premiership match against Harlequins, with the forward close to recovery from an operation on a fractured thumb.
"Calum has had some wires out of his hand, so he might be this week or next week. He's close [to returning], which is really good for us."