Clarke gave players who did not go away with their respective countries three days off after their recent hectic schedule.
But he is unable to switch off himself after a run of five defeats in six games before starting preparations for Monday's clash at Liverpool.
Clarke said: "I can't relax as we're on a bad run and are not winning games.
"Earlier in the season it was nice and easy and everyone wanted to say nice things about you.
"But at the moment it's a difficult time for us and we can't work with most of the players because they've gone away on international duty."