As they would be if they met in nature, the Foxes will be the underdogs when they take on the Lions in the FA Cup fifth round this weekend.
The financial reality of modern football would usually govern that this wasn't the case, with Premier League champions Leicester City boasting a glittering array of talent and Millwall being, well, Millwall, but Leicester's slide down the league table and the south Londoners' form mean the League One club are the fancied side. Just ask Claudio Ranieri:
"I make a lot of changes," he said. "All my team is new and there will be 10 changes again. Millwall have beaten two Premier League teams. We know this and we are underdogs. If they have beaten Bournemouth and Watford then they are above us.
"Our target is the Premier League - that is it. Of course we play in the FA Cup and Champions League and we want to do our best, but our aim is to be safe at the end. The goal is the Premier League. I want to give another opportunity to the players who played against Derby for them to show how good they are.
"Believe me, I don't think about Sevilla (in the first leg of the Champions League last-16 tie on Wednesday), I think about Millwall.
"Our focus is on Millwall because they are in good shape. They beat Bournemouth and Watford. From December 17, they don't lose and they score goals. Everything is fantastic (for them). They fight."
A sold-out New Den awaits them, with its future secure after property developers dropped their pursuit of Millwall's home.
And Lions skipper Tony Craig is not bothered who his side beat - be it Riyad Mahrez or reserve midfielders - after disposing of weakened Premier League opposition in previous rounds:
"It is a great challenge, they have a great squad, a great team and we are looking forward to them coming to the Den.
"I didn't feel disrespected in any way [by Bournemouth or Watford]. They have a squad and they certainly paid a lot of money for those players we played against in those two games.
"I don't think they underestimated us in any way.
"I think we had a really good account for ourselves, if you look back they were two very strong performances from ourselves as well."