Facing flying winger Giggs when taking up the position for the first time could have been a daunting challenge even for someone as versatile as Simon, but our multi-skilled midfielder accepted his mission and came out with honours, if not the points.
Giggs was certainly surprised to see who his marker for the afternoon was.
"When we started he came up and said 'what are you doing here?'", laughed Simon.
"I was going to Old Trafford to play probably the best winger in the country so I didn't know what to expect really. But I did alright in the end.
"I think the way he plays is a bit different now, he seems to tuck in a lot and tries to get through in front so that made it a bit easier as he had to go through more bodies.
"Then there was Silvestre bombing forward and it gave us a lot of space down the right when we got ball and I'm disappointed we didn't win.
"It's much more a case of trying to keep in line with the back four, but I got lost a couple of times in the game, which is to be expected. I thought I did alright and, in the end, enjoyed it.
"I wouldn't like to play there every week though!"
Simon adds that he occasionally had to resist the temptation to push forward into areas he would normally occupy in his wing-back role and paid tribute to the work of Steffen Iversen ahead of him.
"I could see spaces where I wanted to go and I went a couple of times but I was doing a job for the team.
"I've got a lot of respect for Steffen, he was brilliant in front of me - he really worked hard."
Simon Davies lining up in an unfamiliar right-back role on Saturday at Old Trafford drew a quizzical response from Welsh team mate Ryan Giggs.