Carlos Carvalhal said the games caught up with his players following the 3-1 defeat at Charlton in the Championship on Saturday.
The Owls head into the international break having concluded a hectic schedule of league and cup football.
And the head coach reflected that today was just one fixture too many:
“My players played with a lot of heart today but not so much energy because we could not match what the opposites had.
“But I am not unhappy with the players, in fact it is the opposite because they have been fantastic.
“We have just had three games in a week, we have played Arsenal in the cup, and these games have all been played at high intensity.
“I said before the game that we could do with the international break last week and I think we saw today that was correct.”
Carvalhal also saw three players do down with injury at The Valley, all of whom will be assessed over the coming few days.
He added: “Loovens had to come off with a muscle injury and it looks like Hunt and Bannan had knee problems.
“But this is what can happen, this is the Championship, so let us see the extent of the injuries and we hope they will be OK for when we return after the break.”