Gary Locke revealed his growing concern about the toll so much football may take on his youthful and increasingly thin Hearts squad.
The signing ban imposed on the Tynecastle club for going into administration, in addition to a 15-point penalty, is biting hard at the Edinburgh club who are 19 points adrift at the bottom of the Scottish Premiership table and odds-on for relegation.
The club’s administrator, Bryan Jackson, earlier confirmed he will make a second bid to have the transfer embargo lifted and will, as one thread of his argument, cite a possible threat to the health and safety of the young players.
“I am really concerned about it,” said the Hearts boss.
“I haven’t hidden that fact and I have said it from day one.
“You are worried about burnout, you want to give them a rest at the right time.
“It is very difficult. I know a long hard season can take it out of you when you are an experienced player but when you are a young player it is even worse.
“I had it myself when I came into the Hearts first team which was full of international players, at 17.
“I hit the 20-game mark and then the manager took me out of the team because my form dipped and I needed a rest.
“Unfortunately, I can’t do that with the majority of them.”
Locke has been unable to name seven substitutes in several games recently - there were only five in the 2-0 home defeat to Partick at the weekend - and insists there is “no chance” of filling the bench when Motherwell visit on Saturday.
And when asked if there could come a time when he will be unable to name any substitutes at all, Locke said: “Possibly, possibly.
“At this time of the year unfortunately, there are a lot of bugs going about and two or three of the players have been laid low, Callum Tapping being the new one this week.
“There might come a time when what will happen is that I will have to put a 16-year-old kid who has just left school on the bench, but what can you do?
“It is not getting any better. Danny Wilson was laid low with a tonsillitis bug, he has lost about seven pounds in weight, it has really taken its toll on him.
“Kevin McHattie is struggling with injury, Callum has a bug as well so he is extremely doubtful for the weekend and the other boys who are injured are still out.”