The Scotsman was Everton boss the last time he managed there but will instead lead United out against their North West rivals in the lunchtime Sky Live clash.
"A lot of families in this city are split - some are red, some are blue," Johnson told Liverpool's official website.
"I'm sure the Liverpool fans will still see him as part of Everton so I'm sure to those families it will add a little more spice."
Moyes will want to record his first victory at Anfield having failed to do so in 11 years at Everton.
But Liverpool have won their three matches in the Premier League and Capital One Cup this season to leave Johnson in determined mood going into the game.
"Obviously the objective for this weekend is to win. We've started well and we want to keep the run going," he added.
"It's the last game before the international break so it would be good to finish that period with three (league) wins.
"Like I've been saying for many years, the target is to get into the top four - that is our objective, it's what the club wants and needs.
"That will definitely be the aim. We just take each game as it comes and hopefully we'll be there or thereabouts."