Johnson, 33, the third youngest manager in the Football League behind Adam Murray and Alex Neil, locks horns with a familiar figure in Clough, having briefly played for the Blades chief during his tenure at Derby County.
While Johnson is in only his second full season of management, Clough, 49, has 15 campaigns under his belt with the Blades, Derby and Burton Albion and has a clear edge in the experience stakes.
But age is proving no barrier to Johnson, yet to be beaten in seven matches in charge of the Reds, who can move within two points of the fifth-placed Blades with victory this lunchtime.
Johnson admits today’s eagerly-anticipated derby with the visitors in front of an 18,000-plus Oakwell crowd, including 5,000 United fans, represents the most exciting assignment of his managerial career to date.
He urged his side to continue to show no fear in a season which can rightly be labelled as the ‘Great Comeback’ following the ‘Great Escape’ campaign of 2012-13 when the Reds miraculously staved off relegation.
On the task facing Barnsley, who were in 19th place in League One after the Valentine’s Day programme but who are unbeaten in nine, Johnson said: “We have got to go into it with no fear. We have come off the rails from nowhere and it’s very important we play like that.
“The players are in confident mood. Make no mistake, we are playing a very good side with a good manager who knows the division and it will be really tough like it was against Preston and Bristol City.
“But we are up there on merit and want to make sure we close the gap on them.
“If we can win, it will really set us up for the last six games as it would mean we would drag Sheffield United back into our little pack. When you are being chased, it’s a different feel to being the chaser and our players are certainly looking to claw back the points.
“The boys are ready and up for it and fortune favours the brave.
“It’s a great fixture and one that makes me want to put my boots back on. I was always a big-game player and feel the same as a manager. This is probably one of the most exciting games, if not the most exciting game that I have had.”
On pitting his wits with Clough in the derby cauldron, he added: “Nigel had a front-row seat with one of the best managers and characters in the world.
“I have a huge amount of respect for him. I played for him for a month for Derby and it was unfortunate due to finances that we couldn’t get a deal done.
“But we have always stayed in touch. It’s the pupil against the master if you like.”
Victory today would secure Barnsley just their second league double over the Blades after beating them twice in 1996-97 en route to promotion to the top-flight.
But it is play-off points not bragging rights that are concerning Johnson, while for Clough, it is all about consolidating their fifth-placed position and not dropping towards the pack with around eight sides still having designs on the top six.
United manager Clough said: “Barnsley have been on a run similar to us at this time last year. The confidence flows when on a run like that. It goes right through the team.
“When you start at 19th, you are not really saying, ‘The top six is an aim’. As you get closer, that can change. But I still feel Barnsley are in a nothing to lose situation.
“A few weeks ago, no-one expected them to be anywhere near it. Now, though, they can keep going to the end. The only people not under pressure are (leaders) Bristol City.
“We are in it along with loads of teams. That is the thing. It is not just one team that is chasing. There are half a dozen or more who fancy their chances of reaching the play-offs.
“To me, that makes it much harder. To stay ahead of one or two is different to lots of teams. If you slip up, someone behind you will capitalise.”
On the play-off tussle, Clough added: “I think everything will go beyond Easter before being settled, into the last few games. We are in a great position and we need to understand that. It is in our hands with a five-point gap, that is the key.
Barnsley won’t make or break anything, no matter which way it goes.”
Page 3 - Big match preview.