Martin O'Neill fears Aston Villa's early Intertoto start to the current campaign will end up taking its toll on his players.
The Midlands club reported back at the start of July for pre-season training because of their involvement in the Intertoto, through which they secured entry to the UEFA Cup.
The Villa manager admits he may have to "prioritise" in terms of his targets and ease the schedule for some of his squad during the second half of the season as Villa have one of the smaller squads in the Barclays Premier League.
O'Neill said: "We have been at it, playing competitively since July, because we were involved in the Intertoto Cup.
"At some stage or another, it will probably catch up and then we have to go and prioritise.
"I am delighted with the progress we have made in the UEFA Cup, which is what we set out to do, but at some stage around Christmas time I am going to have to sit down and think about this.
"We have eight more games to play before January. I am delighted with the progress but the boys have put a big effort in.
"Someone pointed out that we by Christmas we will have played nine or ten more games than by the same stage last season.
"Against Manchester United on Saturday, you saw Gareth Barry, having played in mid-week for England, trying to kick one clear on the edge of our penalty box in the 93rd minute of the game.
"It was a fantastic effort but that eventually takes its toll."
O'Neill insists, though, his players are retaining their enthusiasm despite the hectic schedule.
"If we have a chance of making progress, I'll see about things but at the moment players love to play," he added.
"Gabby (Agbonlahor) wants to play every single week so does Ashley (Young) and that is important. At the moment they are really enjoying themselves and why not?"