Klopp feels Trent Alexander-Arnold is paying the price for the commitment he has shown to Liverpool and England.
The 20-year-old defender has already achieved more than most players, after making an apperance in the Champions League final and playing for the Three Lions at the World Cup.
However, his recent performances have not been up to the expected high standard and he was substituted at half-time during Liverpool’s 2-0 defeat to Red Star Belgrade on Tuesday night.
Klopp had offered the right-back an additional seven days of rest after this return from Russia, but Alexander-Arnold only took two weeks’ holiday.
The Reds boss feels Alexander-Arnold may now be counting the cost of choosing to return to pre-season training early.
Klopp said: “Trent has played constantly. I have spoken to him about it – but not along the lines of ‘this is good’ or ‘that isn’t’. It’s more general advice. He is still a very young boy. He had two weeks off in the summer. That’s really not a lot.
“We constantly try to keep an eye on him and fitness-wise what he needs to do with the group. Actually, he’s in a good place at the moment.
“He has played a lot of football. He will play a lot of football – that’s the good news for him. It’s more important that he stays injury-free. What’s happening is fine and normal. These are usual things.
“It won’t be the first time or the last time in his life that everything isn’t 100 per cent but he’s still an outstanding player and really important to us.”
With Alexander-Arnold called up again to represent his country in the next fortnight, there aren’t too many opportunities for the Reds’ boss to rest the youngster.
Involvement in the Champions League has only added to the defender’s workload as Klopp admitted he was choosing from almost a fully-fit squad for the visit of the Cottagers this lunchtime.
The German added: “Trent is important to the way we play. But we do have an option to change it. It’s good for us if we have a good number of players to work with.
“To be honest, I’ve been lucky. I’ve always worked with good right-backs. I had too many at Mainz. I had Lukasz Piszczek at Dortmund. He was fantastic.
“So for Trent to be performing as he is at his age is quite exceptional.”
Fulham boss Slavisa Jokanovic is urging his side to learn from Red Star Belgrade’s victory.
“The fight Red Star showed, they way they worked, is exactly what I want my team to show,” he said.
“In the end it was just one more surprise result in football. But it showed you never know what happens in this game.”