His arrival, deemed so important by Glenn Roeder as much for his influence off the pitch as on it, plus the other January transfer window recruits, coincided with other players who had been on the long term injured list getting back to fitness.
"The players have known about the position all along but when the manager brought a few new faces in it gave everyone a little lift, put a spring in everyone's step, and made them fight for places," says Les.
"The main thing is there has been competition for places in those last six games, whereas early in the season I think there were quite a few injuries here.
"They have got that now and everyone is on their toes - and fighting for the cause."
Les also claims that communication between the players has been key, adding:
"We have had a few meetings, everyone has vented their feelings about the situation, and everyone is progressing."
But he insists that the real talking has to be done on the pitch and adds:
"We are down here making the right noises and they will be up there making the right noises; at the end of the day, you get on the park and give of your best, and that is what you have got to do.
"And if we give of our best we will get the three points."
Battling against relegation is a novel experience for Les, but he has no regrets about his move to Upton Park.
"It is a new experience and I have never been in this position at this stage of the season," he says, "but when I left Tottenham to come to West Ham I knew what the position was and what we were fighting for - and nothing has changed.
"It is nice that the manager thinks I have been an influence and hopefully I can help with that influence on Saturday as well.
"What we have got to do now is continue our six game unbeaten run and with five games left, if we can, we have got a good chance of staying in this division."
While Bolton's side is filled with foreigners such as Ivan Campo, on loan from Real Madrid where he picked up a Champions' League medal just three years ago but where he now can't get a game, Icelandic captain Gudni Bergsson, Danish leading scorer Henrik Pederssen, former French international Youri Djorkaeff and Nigerian Jay Jay Okocha, West Ham's side is largely British - with, of course, a fair sprinkling of players in or around the England squad.
As a former England player himself, Les knows his team mates could go on to become England regulars, but he says:
"There is tremendous potential at this club and it is unfortunate that we find ourselves in the position we are in - but unfortunately, potential doesn't win you games.
"It is about producing with that potential you have got, and unfortunately there have been injuries and different reasons for things not going according to plan this season."
As for the tension surrounding the game and the effect it might have on the younger players, he says:
"It is a small part and parcel of football and it is pressure that will stand them in good stead for the years to come."
Les is particularly impressed with Jermain Defoe and he adds:
"Jermain has been fantastic; I have kept an eye on him since I was at Tottenham as I have always seen him as a very exciting young striker and I have always been very impressed by what I have seen.
"Hopefully he will keep learning and progressing - and become a very important player for West Ham in the years to come.
"But now we have to think positively about getting a result on Saturday - and I am sure we can."
One player who surely has the potential to become a fixture in the England side for many years to come is Glen Johnson, who is looking forward to the weekend challenge and says:
"This easily tops the West Brom game and the game means a lot to me, but we will take it like any other match and play the way we can - I haven't been playing too long but this will be my biggest game."
Glen's rise has, to use the cliche, been meteoric, and he adds:
"It has come quickly but I wouldn't say it has come too quickly."
He insists the Hammers can pull clear and adds:
"It would have been nice to get the three points against Aston Villa but confidence isn't low and I think we have more ability to get out of it.
"Everyone is working hard and playing at their best so it is looking good."
And Glen agrees with 'Sir' Les that increased competition for places in recent weeks has led to an improvement on the field.
"It helps everyone; the better players you play with the better you will be and I am learning from people like Rufus and Les all the time," he says.