Johnson was appointed on Friday as a replacement for Ian Sampson and will not have Davis available as he continues to nurse an Achilles injury.
Caretaker manager Malcolm Crosby will pick the side and hinted that he will not make major changes but is boosted by the return of January signing Shaun Harrad.
Striker Harrad missed the 3-2 defeat at home to his former club Burton, which saw the end of Sampson's 17-year stay at Sixfields, through suspension, but he should start.
Defender Craig Hinton has had an injection in a long-standing knee injury this week and he will be out for around a month.
Midfielder Ryan Gilligan has returned from his loan at Torquay a week early after suffering a family bereavement but cannot play until the Macclesfield game on March 12.
Source: PA
Source: PA