But O’Neill is convinced Eriksson has established the right balance to help players train and remain fit for clubs.

O’Neill told the Celtic View: “Whatever you say about Eriksson – and without knowing too much about his training methods – he has clearly been sympathetic to club manager’s views.

“I think he realises that, if players have played enough games, their fitness will generally be OK, with individual exceptions like Wayne Rooney, who obviously required a bit of extra conditioning last season.

“But other managers and coaches seem to behave like the players are arriving with them having not done any work for the past six months, and that training sessions morning, afternoon and evening are the best thing to get them fit for the Saturday.

“That’s obviously concerning.”

He added: “It’s interesting that your weeks of worry are magnified when your players are away from the club.

“When they’re here, you’re at least comforted by the knowledge that you’re in charge of the training sessions and, perhaps, even more importantly, the number of training sessions they do.

“I won’t name any names but some of our players certainly complain that they’re asked to do an awful lot of work to get them just right for that game on Saturday – often to the detriment of their overall fitness.

“It is worrying when they’re out of your control.”