Liverpool have been playing back-to-back games in the past few months.
The Reds will be visiting Villa Park for their midweek clash against Aston Villa.
This will be their 12th game in the span of 38 days and the manager has somehow managed to utilise his squad to maintain fresh legs throughout.
Many players could be in the line for rotation as Klopp needs fresh legs for their FA Cup final against Chelsea on the weekend.
The German manager has found the perfect balance between rhythm, continuity and stability in the last few games.
Klopp said: “It’s a challenge, to be honest. Very often, the decisions get easier with all the information I get from the medical department because then I don’t have to choose from all of them, only a few.
“In the short periods between the games, I didn’t get the final information.
“When I leave here, I’ll go to the medical department and collect some more then we will see.
“Is it difficult? It’s challenging, that’s it.”