But the Blues boss insisted there were reasons for a loss that stretched his side's woeful run without a home league win to 14 matches.
McCarthy was unable to name a striker in his starting line-up after Ross Hannah, Harry White and Nyal Bell were ruled out and James Akintunde was deemed fit enough only for a place on the bench after coming off injured in the 2-1 victory at Aldershot Town 48 hours earlier.
But, after a lacklustre and laboured performance, those factors cut little ice with a set of supporters who have now seen their team take just three points from the last 42 on offer at the Swansway Chester Stadium.
After the final whistle there were boos and chants of 'out, out, out' directed toward the under-fire manager.
McCarthy, who was disappointed by the nature of both of the goals Macc scored, said: "It was a tired-looking performance. The players looked a little bit flat and we never got the energy levels we wanted in front of a home crowd who were excellent.
"That group of young lads, who were on the drums, they came and delivered their bit. They were outstanding and I need to thank them. They sang and sang and sang to try and get us going.
"We did our work and our preparation so all I can offer up for it is it looked a tired performance and the striker situation hurt us. We got away with it second half (on Saturday) with (Lucas) Dawson up front but actually it's a completely different position to play.
"Lucas Dawson will always start looking deep to come toward the ball and it drags everything back. The back four were deep and we can't make any excuses there today because I had those people fit, so I was disappointed with that aspect of the team. That should have done better.
"But the other stuff I think can be explained. We tried everything, we rotated, we changed systems, and we did everything we possibly could to lift it and try and find an answer."
Asked directly about the supporters' reaction at the end, McCarthy said: "The fans were outstanding. I asked for them to come and I'm two days away from an outstanding result at Aldershot.
"They were great at Aldershot, they were great against Sutton, when they gave us the lift, and they were for us from the start of the game today.
"I get the frustration but we did everything we could to plan for it but it was just a very tired performance and I'm missing four really key players, which make a complete difference to that line-up.
"Players just can't play centre-forward but we have to play someone up there. I played a centre-half, centre-midfielder, a wide right player (up there) and we went 4-4-2 and 4-3-3. It feels like I've worked as hard as the players on the sidelines to try and affect things and try and change it.
"I know how much it means to them (the fans). They were outstanding today and I'm desperate to give them everything they want and I'll keep working hard to do so."
McCarthy was then questioned by the written media about the winless home run and the nature of the display.
He said: "In terms of the fans' (feelings), I've acknowledged. Anybody who has been here as a fan at this football club or spoken to me or seen me I think will say how well I treat them and how well I respect them.
"I've worked hard to set up a team again and the situation is four of my key players are unavailable and it was a tired performance at home. That's the situation and I think under those circumstances there are reasons that might make it acceptable.
"It's not anybody who is not trying or working hard. It's not a manager (who's not) out there preparing tactics, putting training sessions on, who isn't bright, and doesn't try and do everything he can for this football club.
"It does feel as if none of you (the Press) mentioned that Aldershot had not lost in 14 games at home and we've gone and beat them and what a result that is."