Tottenham manager Antonio Conte said Harry Kane is running on empty just over a week before he leads England into battle at the World Cup.
Conte blamed a lack of other available options for starting Kane in Spurs' 2-0 League Cup defeat to Nottingham Forest on Wednesday.
The England captain was replaced on the hour mark, but has now started all of Tottenham's 21 games in all competitions this season.
Conte is currently without Son Heung-min due to a fractured eye socket, while Richarlison and Dejan Kulusevski are making their way back from injury.
"He was really, really tired. Yesterday we had a soft training session, really soft and at one point he stopped himself to recover energy," said Conte.
"I repeat he's okay, it's only fatigue, but it is normal because Harry played every game.
"When you have a player like him it is difficult to decide not to play with him."
To make space in the schedule for a first mid-season World Cup, the group stages of European club competitions were squeezed into a two-month period.
By the time Spurs face Leeds on Saturday, they will have played 13 games in 42 days before the World Cup break.
"Harry Kane showed to be a really good man also," added Conte as he thanked his players for not pulling out of games to save themselves for their countries.
"But not only him it is the same for (Pierre-Emile) Hojbjerg, (Rodrigo) Bentancur, (Ivan) Perisic, (Eric) Dier.
"We faced a bad situation about the injuries and we arrive at the end in difficulty. Now we have to try to rest and recover energy."