Newspaper reports claimed that striker Robbie Fowler, in particular, reported back to Carrington this week a lot heavier than what he was at the end of last season.
"The only thing I want to say about that issue is that Robbie has come back and he is three pounds over the weight he was at the end of last season," Keegan told the club's official website.
"We have got twelve players out of a squad of forty who are slightly over what they should be."
"Most of them are the kids, some of who are seven or eight pounds above normal, but that is only because they have been growing so much over the summer."
"Some of the senior professionals are four or five pounds over what they finished on."
"But I am absolutely delighted with Robbie. Like everyone else, he has got to get fit and that is what you have pre-season training for."