Maribor lead the Slovenian league by six points after winning seven and drawing two of their nine matches so far, scoring 20 goals in the process and conceding just four.
But Milanic is taking nothing for granted and has made sure to do his homework ahead of the Group J clash tomorrow night.
"Through analysis we find the bad spots of Panathinaikos and I hope that we find a way to overcome them," Milanic told a pre-match press conference.
"We are aware that we have a difficult task against a quality opponent and a prominent member of European football. They have a range of high-quality players, from young talents to those who played in the major European clubs.
"All this must be respected, regardless of whether our clear goal is that we want to be better than last year in the group stage.
"Panathinaikos we would describe as a very robust, compact, experienced team. In their previous matches they played in two different systems, 4-4-2 or 4-3-3.
"We must pay special attention to Ibrahim Sissoko, who has technical capability and is a fast player."
Panathinaikos have won one, drawn one and lost one of their three league matches this season, but only have two points after starting the season with a two-point deduction due to crowd trouble last season.
The Greek side missed out on a place in the Champions League group stages after losing 2-0 on aggregate to Malaga in their play-off tie last month.