The Wearside-based club failed to retain their place at the top of the League One table when they suffered a shock 4-0 defeat to Portsmouth a fortnight ago.
Sunderland bounced back from their loss to Portsmouth with 2-1 victories over Lincoln City and Manchester United Under-21s in the EFL Trophy, with a host of youngsters shining for the side.
Although Sunderland go into the league match against Gillingham on the back of two consecutive wins, Johnson has admitted that he is still reeling from his side’s shock defeat to Portsmouth.
Johnson insisted that the Black Cats have a point to prove when they face Gillingham and explained that he is aware of what to expect from the Kent outfit.
“It is a big game [against Gillingham]“, Johnson told SAFC TV.
“I’m still reeling really on the back of the Portsmouth game and we’ve got a point to prove.
“We know their style, we know what to expect from Gillingham.
“We are going to have to cope with that, but we’ll also have our opportunities.
“It’s another big game for us and another step we want to take forward.“
Having bounced back from their defeat to Portsmouth with two consecutive wins in the EFL Trophy, Sunderland will be hopeful of getting back to winning ways in the league against Gillingham on Saturday.