The Gunners were staring elimination in the face when Pires went down in the area after going past Anthony Reveillere.
Referee Kyros Vassaras was not fooled and handed out a caution to the French international.
Pires felt his card was deserved, saying: "I acted a bit and faked to try and get a penalty - but it was never a penalty and what's more I richly deserved my yellow card.
"In the past I've seen penalties awarded for nothing and, as we were in the 92nd-minute of the match, I thought: 'Why not try it?'"
Upon picking himself up, Pires was surrounded by angry Valencia players and lashed out at Reveillere.
The Frenchman was full of remorse, saying: "I regret kicking him because it's not something you should do and it's not an example to show youngsters.
"It was a case of end-of-match nerves.
"However, there had been a little altercation between us just before and he didn't come and say sorry.
"I was mad about it and, of course, we were losing - but it wasn't meant to be bad."
Pires was also disgusted by the treatment handed out to Arsenal`s black players by a section of the Valencia crowd.
He continued "I really didn't think I'd ever see that again in a football ground.
"There were some spectators behaving disgracefully towards our black players, particularly Patrick Vieira and Thierry Henry.
"I saw Patrick's face and he was completely distraught. He was really crushed by that behaviour.
"When you're on the pitch, nobody should be insulted and whistled at like that.
"When you see that all you want to do is go home."
