The Cobblers sit only two points above Albion in the npower League Two table and Johnson knows the importance of the game if his side are to avoid relegation.
"The next couple of games are big for the club and it would be great if we could get a lot of support at Burton," he told the club's official website.
"We need to have that cup final mentality because when that win comes we will enjoy it like a cup final. Whatever the fans' opinion is of anyone or anything at the minute, we all need to be together and be positive for the lads.
"A good support at Burton will be worth that extra man the way the lads are at the minute and everybody needs to play their part. If we are all together everybody will take the acclaim if we come out of Tuesday night with a positive result.
"You get key games in a season and this is definitely one of those. This is our game in hand and although it is very late in the day a win could still kick start our season."
Source: PA
Source: PA