Nine years after Manchester United were forced to play Celtic in Seattle Sounders' impressive city centre home because the MLS side were not deemed strong enough opposition, they will face their hosts in front of over 60,000 fans at CenturyLink Field tonight.

It promises to be a noisy affair, with the Sounders' resident band providing the backdrop to an especially enthusiastic 'March to the Match', such a feature of home games in this part of the world.

Keller and his team-mates will then attempt to secure their own place in Seattle sporting folklore by downing the 19-times Premier League champions.

"My parents and friends had such a hard time trying to watch me play when I was in England," said Keller, who spent 12 seasons in England overall, including four years at Tottenham.

"Now they could watch every game if I was still playing over there. It just shows the state of the game.

"It means there is a lot of competition for the MLS.

"In the morning, you might get up and watch your Premier League team, or German, or Spanish. Are people also going to commit to watch an MLS game?

"But I guess the most important thing right now is to have people watching and enjoying the sport."

Keller could have joined United at one point, only to reject the opportunity due to fears he may be forced to spend extended time on the bench.

It is not a matter of regret for the 41-year-old.

However, it does mean tonight's encounter with have special significance.

"This is a big occasion for a lot of our guys," said Keller.

"They watch Manchester United on TV, so to have an opportunity to test themselves against them, albeit in a friendly, is fantastic.

"Of course, it is a particularly significant occasion for me but I look upon it more from a club perspective, and US soccer as a whole.

"I am very proud the club has been able to give Manchester United a training facility like the one they have been working on.

"To be able to come to a stadium like ours and have it sold out with people who are Sounders fans is fantastic.

"People are turning up to see Manchester United and there will be excitement at being able to watch stars like Wayne Rooney.

"But United might get a shock. There will be a few rooting for them but they will be left in no doubt they are the away team.

"That doesn't happen too often when teams travel to America."