Jon, who has signed a further two months, says:
"It is brilliant for me; I wanted to stay the three months in total anyway.
"I have got two months to try and prove something; it is not in my hands, all I can do is play as well as I can when I am given the chance and hopefully there will be something at the end of it."
Jon made his debut against Sheffield United, another club where he has been on loan, and it left Blades' manager Neil Warnock bemoaning that he had gone back on a 'gentleman's agreement'.
Not so, says Jon, who explains:
"I never said that, I think it was because I had quite a close relationship with Sheffield United.
"I spoke to him a fair bit and saw them as a potential club where I would go to but the chance to come to West Ham came along, I was left in the dark a little bit, so I decided this would be the best thing for me."
As for Saturday's big game against the table toppers, Jon adds:
"Norwich are top of the league and it is going to be a massive game; I think we should be up there where Norwich are.
"The next two months are going to be massive for us because if we can go on a good run we could potentially be in the top two going into the last month of the season.
"They are on fire at the moment but we have a game in hand and if we can get three points off them as well that will be of great use to us - and it will make it a lot closer for everyone else.
"But it is important we beat Norwich on Saturday and carry on the good run we have started."
So it will be all-out attack?
"I don't think we could play any other way; we are an attacking team that likes to play nice, attractive football whoever we are against," says Jon.
"Hopefully we can do that on Saturday and come away with three points."
Jon was ineligible to play his 'parent' club Fulham on Saturday, and he will again be spectating for the replay on Tuesday.
How did he see the first game?
"From what I could see we were unlucky against Fulham; we had the better chances and should have won it, so it is unfortunate that it went to a replay.
"That was against decent Premiership opposition, so it is a marker of where we should be and hopefully we will be getting that every week next season.
"Some of the Fulham boys that I spoke to definitely thought they got outplayed and were lucky to still be in it, so coming from players who played in the game it gives all credit to West Ham.
"I think they can play better but they only played as well as we allowed them to and we distracted their game a bit which is what the gaffer had worked on all week - to take the game to them like that.
"I don't know if they were expecting that and we deserved more than we got."
As for the paltry crowd, he adds:
"That is sometimes the way it goes for Fulham; the boys would have liked a full stadium and they didn't get the result they wanted, either.
"Going from that game I think the boys will be on a high going into the replay.
"It will be a much bigger crowd for the game at Upton Park; hopefully the crowd will get behind us and spur us on for the nice, easy draw in the next round!
"Obviously that would be a massive game and going to Old Trafford is the biggest game you can get.
"If we can come out of the Fulham game with that at the end of it would be brilliant for us."
Jon is aware that the Hammers lost 6-0 at Old Trafford last year in the Cup, but insists:
"I would be very surprised if that happened this year because I am certain the team has a lot more confidence than the one which went down last season.
"Confidence will play a big part, we can definitely hold our own, and on our day, who knows what could happen?"