The former Swindon boss watched Saturday's 2-1 Premier League defeat by Aston Villa from the directors' box at the Madejski Stadium.
McDermott was sacked as Reading manager on Tuesday, prompting speculation the Italian could be in line to replace McDermott.
However, Di Canio told BBC Sport: "It was just a coincidence. I was there only to watch the game.
"I was sat with Stuart Pearce at Reading and we had some discussions about the game.
"I want to watch games at the top level and [the Madejski Stadium] was full of passion, so it was good to go there.
"Next time it could be Swansea or Southampton or Tottenham, I don't know, but this is what I am going to do for the next few weeks."
However, the 44-year-old former Sheffield Wednesday and West Ham striker, who resigned as Swindon manager last month, added: "It is my ambition to manage at the top level."
And besides he doesn't want to look like fool when they offer it to another- jericho