Sam Allardyce believes a lack of winter break is hampering Premier League clubs in European competition.
Chelsea were eliminated from the round of 32 in the Champions League by Paris Saint-Germain on away goals on Wednesday night -- whilst Manchester City and Arsenal both need to turn around first-leg defeats to Barcelona and Monaco, respectively if they are to advance.
Liverpool and Tottenham have been knocked out of the Europa League with only Everton still standing and Allardyce feels a heavy festive schedule always catches English clubs out.
"I think, like I have before, that we don't help ourselves with our fixture list," the West Ham boss said. "Playing as many games as we do through Christmas and New Year and not having the opportunity to shut the league down for a few weeks gives every club that plays in Europe a disadvantage.
"When they come back to playing in Europe they may have a considerable amount of injures in certain areas and mental fatigue kicks in on players -- that is bound to have an effect when other teams have had the opportunity to take a break."
Swansea boss Garry Monk hailed the entertainment level of the Premier League but believes English clubs still lack the tactical nous of their continental counterparts.
"I've always said the Premier League is the best league in the world but more so for entertainment rather than technical and tactical situations in countries like Spain," he said. "The Premier League is the best league in that it is the most entertaining, highest tempo, most ferocious and so much happens.
"Whether we need to improve on the tactical I'm not sure but we've got some of the best managers in the world in this league. It is very fine margins at that level as games are won and lost by one or two moments in a game.
"Looking at those players in those Premier League teams you think they would do better in those competitions. So I'm not sure if it's one of those seasons or if there is a fundamental problem."
Tim Sherwood feels the level of competition in the Premier League means there is no let-up for sides chasing success at home and abroad.
The Aston Villa manager said: "What's tougher for English teams is the fact there are no easy games in this league whereas in Spain and France you can perhaps play against the lower sides and put a reserve side out and still win if you're a top team.
"You can't do that in the Premier League, you have to play each game as if it's a cup final. I think it's the most competitive league. I think it's the strongest league in the world, I listen to a lot of pundits talking about the tactics are wrong, English tactics are "this and that" but I didn't see an English manager there.
"I've seen a manager who has won the competition on a few occasions and who knows what he's doing. It's just on a one-off game and you get beaten by a very good PSG team. That can happen in football."
Whilst Allardyce, Monk and Sherwood all had their own ideas on why sides were seemingly struggling in Europe, West Brom head coach Tony Pulis insists Chelsea's exit on Wednesday does not mean English clubs are failing.
"It was one game," he said. "I watched the game and I thought PSG were good and deserved their victory. To write off Chelsea or English clubs in general after one game [is wrong], especially Chelsea, who have been outstanding this year but had a bad night.
"Unfortunately it was the wrong time to do it. Jose will be very, very disappointed, as will the players and the club, but I'm sure they'll bounce back."