Cobus Reinach will be available for Saints' trip to Saracens on Saturday after missing last weekend's win against Bath.
Reinach was initially named on the bench for the Gallagher Premiership game at Franklin's Gardens but was withdrawn due to a minor neck injury.
Alex Mitchell played the full match, scoring a crucial try and claiming the man of the match award.
Connor Tupai was among the replacements, though he did not get on to make his Premiership debut.
And Reinach now looks set to replace Tupai in the matchday squad at Allianz Park on Saturday after taking a full part in training.
"Cobus has taken part in full training today and looks as terrifying as ever with the ball in hand," said Saints assistant coach Matt Ferguson at Tuesday afternoon's media session.
But Teimana Harrison (hamstring) and Piers Francis, who was forced off due to concussion last weekend, remain doubtful.
"Piers recovered after the game and he's now in the hands of the medical department to see how he is," Ferguson said. "He's been around today, laughing and joking so that's always a good place to be.
"Tei's still working towards a return and hopefully he will be there or thereabouts for the weekend."
Dan Biggar looks set to be available again for Saints, just as he was during Wales' previous Six Nations rest week.
Biggar started the game against Sale Sharks at Franklin's Gardens earlier this month, having expressed his desperation to play for Saints during his week off with his country.
And after a superb showing from the bench in Wales' win against England last Saturday, Biggar is likely to be eager to start at Allianz Park.
"We'll probably see him later on today and we'll see where he's at," Ferguson said.
"I'd imagine he's in good spirits after what happened at the weekend!
"One thing with Dan is that his desire to put the shirt on and play for the Saints is incredible so if he's around I'm sure he'll be on the selection table."
Talented young prop Ehren Painter could also be back for Saints after missing last weekend's game due to illness, but Dylan Hartley, Courtney Lawes, Andy Symons, Harry Mallinder and Mike Haywood definitely remain on the sidelines.