The England midfielder was the match-winner in midweek as the Hammers edged past Oxford United to reach the Carling Cup third round. It was a tense tie, with Parker's close-range finish only coming deep into added time. "They are a well organised side. It was difficult for us. In the end it was pleasing to get the goal and get the game over in 90 minutes."
The overriding mood afterwards was "a win is a win" and Parker was in optimistic mood for the weekend trip to Old Trafford.
"We need to go there and do something similar to what Oxford did to us," he said. "We need to be well organised and when a chance comes we need to take it. It is going to be difficult like it always is but you never know."
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"A win always breeds confidence. It is a good thing. We have got two difficult games coming up obviously. There is no hiding that fact. Man United and Chelsea [on 11 September] are not easy games but we go into them with a win which is helpful. We are under no illusions that it is going to be difficult."
Parker was captain for the night against Oxford but skipper Matthew Upson, along with the rested trio of other England players in Robert Green, Kieron Dyer and Carlton Cole may all come back into the manager's thinking. Parker, though, praised the youngsters that came in - most notably debutant goalkeeper Marek Stech.
"Marek did very well. It was his debut and he did really well. That was pleasing. I think the days are gone when lower league teams come to big clubs and everyone thinks you can beat them six or seven. A lot of people coming might have thought that but well organised teams are hard to break down.
"Obviously we fully expected to win and we did that in the end but we made hard work of it. It was a little bit of relief. It has been a hard start to the season and it was a difficult game at times. It was pleasing to win and hopefully we can now we can push on."
Manchester United would be a perfect game to do just that and Parker reminded that "anyone can beat anyone on their day", although he also followed his manager's line in urging patience.
"We have got a lot of new players in and it is going to take time to gel. A new manager has come in with his own ideas and it is going to take a little bit of time.
"I understand that sometimes in football you don't always have time. The quicker we can adapt, the quicker we can get used to each other and pick up results, the better for everyone."