The 29-year-old snubbed a move to the Emirates in June after the Gunners triggered his £22million release clause and signed a new deal at the Foxes instead
Arsenal boss Arsene Wenger said this week the England forward gave him no reason for his decision as he comes under increasing pressure following a lack of signings.
They go to last season's shock Premier League champions on Saturday and, ahead of the visit, Ranieri believes Vardy does not need to justify himself to Arsenal
"No, no, no
We have only to prove to ourselves that we are stronger, that we want to win," he said
"Jamie wanted to stay here and wanted to give his signature to say 'thank you' to the fans, his team-mates, the chairman, everybody
It depends on the character of the players and the family
"He said 'we want to build again and I don't want to go'
He knows it will be hard but it's good
"He is a fighter man
I hope everybody plays with an extra edge."
Arsenal beat Leicester twice last season, with the Foxes only losing one other league game to win the title by 10 points
Vardy, who scored 24 goals last term, netted three times in the two games against the Gunners
The Foxes lost 5-2 at home in September and have not been beaten in the league at the King Power Stadium since, while they suffered a last-minute 2-1 defeat at the Emirates in February
Ranieri, who has a fully-fit squad, added: "We are champions, but we are underdogs with a lot of big teams, because now we are building a team.
"(Manchester) City - how long? (Manchester) United - how long? Since (Sir Alex) Ferguson was manager
Tottenham, Liverpool - everybody
We are underdogs, it's normal.
"Now the story is finished
Now there is a new story
We lost the first match (2-1 against Hull) and now we have to fight to get something good
When I go on the pitch, always I'm positive."
Source : PA
Source: PA