The Yorkshire club have won four and drawn one of their five matches since Johnson was appointed last month, having also secured victory in the two matches before his arrival.
However, Barnsley now face a Preston team who have lost just once in 12 league matches and with third-placed Swindon Town not in action this weekend, their grasp on second spot could be tightened.
Leaders Bristol City face Walsall in the Football League Trophy final on Sunday, so a victory would see Preston move eight points behind Steve Cotterill's men with a game in hand.
The Lancashire club are expecting a vociferous following at Oakwell, with the match chosen as "Gentry Day" - a tradition of supporters to mark an away game as a way of remembering Preston fans who have died in the past year.
"It is a great idea that takes place every year and we are looking forward to seeing them all in their suits and bowler hats," manager Simon Grayson told Preston's official website.
"Our performances away from home have been really good and they have been backed by some fantastic support.
"Hopefully come Saturday they are celebrating positively again."
Fourth-placed MK Dons ended a four-match winless run by beating Oldham Athletic 3-1 on Tuesday, and Karl Robinson's men will look to take advantage of Swindon's week off by winning at home against lowly Notts County.
Sheffield United's play-off challenge has hit a rocky patch after failing to win their last five matches. The Yorkshire club aim to end their barren run against Port Vale at Bramall Lane, while seventh-placed Peterborough United welcome fellow top-seven hopefuls Chesterfield.
At the bottom of the table resurgent Crawley Town will be eyeing a third consecutive win against fellow strugglers, while Crewe Alexandra and Colchester United play Oldham and Gillingham respectively.
Elsewhere, Coventry City will seek to move further away from danger at home to out-of-form Doncaster Rovers, whose promotion bid has faltered, while Bradford City and Rochdale have home matches against Fleetwood Town and Scunthorpe United respectively.
