The midfielder was distraught after being sent off for two bookable offences after only 27 minutes at Highbury.
But now, at least with the first yellow card against Arsenal rescinded, Simon returns to the international stage he's graced in recent months as Wales take on Azerbaijan in a Euro 2004 qualifier, kick-off 3pm our time.
Wales are unbeaten for a year and Simon has scored in three-successive internationals including the opener in the memorable win against Italy last month.
That victory put Mark Hughes' men in charge of Group Nine and another success over Azerbaijan will open up a gap at the top of the group.
Simon is well aware that they cannot waste that win over Italy. Speaking from Azerbaijan last night, he insisted: "We are treating this exactly the same as the game against Italy.
"We know if we manage to win then we'll be five points ahead of Italy having played the same amount of games.
"It won't be easy out here though but we know what we have to do and we're all confident.
"It's a great set-up at the moment and we all know our jobs when we get out there. It's so professional. Mark Hughes has been first class, we all work for him and each other and we're all determined to go out and win. We know how important this one is."
Simon has certainly tasted the highs and lows of football in the last six weeks.
He followed his goal against Italy with another against Bolton but since then we've suffered four defeats in five games and, of course, he was sent off at Highbury.
"Obviously I'm pleased the first card has been rescinded but the big disappointment was to miss the game," he reflected.
"It was only 26, 27 minutes into it and we all hoped we could get back into the game. There were plenty of tackles flying about as well, so it was disappointing.
"I missed that chance at Sunderland as well and if that had gone in, I'm sure we would have won that game. But these things happen and I'll make sure I learn from it."
Simon Davies is determined to put Saturday's derby woes behind him and help Wales take a massive step towards the European Championship finals this afternoon.