The striker said he is over the injury problems he has had over the course of a long season and is looking forward to completing a dream campaign.
"I have the same feelings as in the World Cup final, only the jersey has changed," Martinez told a press conference on Friday.
"These are the most important matches in the world of soccer and all players want to play them. The sensations are the same and we are prepared to the play the game that we have to.
"We only got here thanks to hard work. The group we have is what matters, it is the most important thing. We're at the last step and we need to seize this opportunity."
After a difficult start to the year, going through a goalless 10-game stretch, Martinez has scored 11 goals in the last 13 games, including in the semi-final second leg against city rivals AC Milan.
Inter are in good form, having won 11 from their last 12 matches in all competitions. Despite being the underdogs against treble-chasing City, Martinez was confident he and his team mates could spring an upset.
"We know that Manchester City are very tough rivals to face, for the quality they have. But we've done our job and we're ready for the task," Martinez said.
"It is the best year of my career. I had the opportunity to play in a World Cup final six months ago and now I will play in a Champions League final.
"I am very happy with the season but also with the moment we are living, let's see if we can crown it in the best possible way by winning the title."
