Saints boss Chris Boyd has allayed injury fears about Cobus Reinach following the scrum-half's withdrawal against Sale Sharks last Saturday.
Reinach was down for some time before eventually getting up and walking from the field in the 55th minute of the 67-17 Gallagher Premiership success at Franklin's Gardens.
But Boyd says he was always planning to replace Reinach at that point and the South African star, who has scored 13 tries in 19 appearances this season, has trained this week.
"We were going to substitute him anyway," said Boyd ahead of Saturday's home game against Bath. "Alex Mitchell was ready to go when that happened.
"He had a minor neck or shoulder sprain but he's trained today so there's no issue there."
Teimana Harrison missed last Saturday's win following the hamstring injury he sustained in the victory against Newcastle Falcons a week earlier.
And Boyd said: "T's problematic as he still has a hamstring injury so we're not sure where he'll end up, but he's pretty close."
David Ribbans was also ruled out against the Sharks due to a hand problem.
"He had a little bit of gangrene in the fingers there but he's better than 50/50 so he's pretty close," Boyd said.
Dylan Hartley has not played for Saints since the win at Worcester Warriors just before Christmas and he has been unable to feature for England in the Six Nations so far.
But he continues to work hard as he bids to return from a 'grumbly' knee injury.
"That grumbly knee is still grumbling," Boyd said.
"He's been working incredibly hard in the gym but he's not at the running stage yet.
"He's working away and when he's ready to play he'll don the Northampton Saints jersey again."