Moncs is out of contract this summer and knows that the curtain could then come down on an eight-year Hammers career.
"I am really enjoying it, just being involved. It could be the last time I put on a West Ham shirt because there are only a few games left and contract wise nothing has been said to me, so I don't really know what is going to happen either way," he admits.
"It doesn't seem too positive but that's the way it goes, and I'm in no position at my age to make any fuss about it. I'd love to sign another year but it looks a little bit grim at the moment.
"But even to get on the pitch for what seemed like only 10 seconds was brilliant for me the other day. I have grown up supporting the club and to run on the pitch it is a buzz every time for me - it might not be for others, but it is for me."
If he is released - and Glenn Roeder is making such decisions at the season's end - John is unsure of his next move.
"We will wait and see what happens, but I have got no desire to play for anyone else.
"I've not earned the money that is going about nowadays as obviously I have been here longer than the others but I have no wish to leave the club.
"It would be heartbreaking to leave and I have kept myself fit and done well when I have played - even this year I have never let anyone down.
"But that's the way football is. Whatever happens you have just got to get on with it.
"Glenn has been great for this club and results wise it went brilliantly for us at the weekend as we have gone above Tottenham and Villa. Results are everything and at the end of the day we are on a good run."
John has been involved in the last three games as sub - and gave the crowd something to smile about when he gave a long lingering look to the behind of female assistant referee Wendy Toms at the weekend when he was warming up against Charlton.
"I was just having a bit of a joke and a laugh to liven things up a little bit," he says, "and she's alright, she took the joke well."
But he does normally give the assistant a playful slap on the head...
"You can't do that to women; it was just a bit of fun."
There was, indeed, some delay in him coming on for Joe Cole deep into stoppage time, after he had looked set to make his entrance a couple of minutes earlier.
"I don't know what happened there. I think the assistant saw something else but it is one of those situations where the result's everything and it gets a little bit tense at the end," he says.
"You have got to be careful who you put on and when you put them on. It's the manager's job and I was just lucky to get out there.
Talking of Paolo Di Canio's recent comments about making way for John at Craven Cottage, he says: "People get swapped about for different reasons, tactical or whatever, it is the manager's decision and to be honest you can't criticise him this year - he has been brilliant.
"Paolo is as good as gold with me and there are no problems with me or him, but he has got no problem with any of the other lads, and he's a great player for us.
"Everyone gets upset at times if they don't feel things have gone how they feel is the right way - I've done it myself in my career.
"I have been upset about certain things in my younger days, though not so much now - but that's football."
And his thoughts on the final run in?
"It would be nice to stay fit and get as many seconds as I can playing for the club," he says.
"Those few seconds meant something to me and it goes down as another appearance for West Ham United when I hang my boots up and look back, so that is good enough for me."