Holders City start their defence at the Etihad Stadium against a Wednesday side who have started well in the Championship, and they occupy sixth in the table after conceding just four goals in their first eight matches
Despite that solid start, City's wealth of talent makes them the overwhelming favourites to progress from Wednesday's third-round tie.
However, Wednesday head coach Gray witnessed City play first hand in Sunday's 1-1 Premier League draw with Chelsea and the 54-year-old is planning to use the knowledge gathered from that game to exploit any areas of weakness.
"I went to watch the game [with Chelsea] live so that was interesting," Gray told reporters. "It will be nice to go the reigning cup holders and Premier League champions so I'm looking forward to it.
"They are all gifted, world-class players. They are technically very gifted. It was a good, enjoyable game.
"They had a lot of possession of the ball so we might just have to defend very well.
"It was a good game and I just felt Chelsea would go on to win it. It just shows the character they've got in the team to go down to 10 men and get a draw.
"I think their strengths way outweigh their weaknesses. Hopefully, I spotted a few weaknesses that we can exploit."
While few predict Wednesday to pull off a famous cup upset, Gray feels his team can benefit from playing without pressure.
"It's one of those games where nobody gives us a chance," he added "We can go there and play relaxed and play with confidence.
"They dominate the headlines but I'm looking forward to the game because I think we can give them a good game."
