Demichelis, 45, and Maresca were neighbours during their time playing together at Malaga, and the Leipzig coach said Tuesday he considered the Italian his "brother".
"I know Enzo very well - he's one of my best friends in football. I'd say we're almost like brothers," Demichelis said Tuesday.
"We lived together - or rather, right next door to each other - in Spain. I'm familiar with his philosophy, his ideas.
"Our kids grew up together. Early on, as players, we both wanted to become coaches.
"We started the journey together. He's very intelligent and pragmatic, and it'll be an honour to take the pitch with him tomorrow."
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The Argentinian, who took over in Saxony in the summer, said Maresca had called him on Monday trying to get the inside scoop of Leipzig's likely starting XI.
"Enzo is a winner. He'll be doing everything he can to win titles with Manchester City," Demichelis added.
"There was a lot of interest in my line-up when we spoke yesterday. We think very much alike when it comes to football...
"Enzo wants to know our line-up. I won't say anything. He'll find out tomorrow."
Demichelis spent three seasons at Manchester City, winning the 2013-14 Premier League title and two League Cups during the period the club were found guilty of having broken financial rules.
The coach said the looming penalties and the potential of having his titles stripped did not concern him.
"I spent three fantastic years there, but it was a long time ago," Demichelis said.
"(The charges are) not interesting, it's a long time ago, football has changed.
"I'm the coach of RB Leipzig and all I want tomorrow is a good game from RB Leipzig."
