The Danish defender faced the Foxes twice last campaign for FC Copenhagen in the Champions League Group stages in what were tight and narrow affairs.
After the then-Premier League champions recorded a 1-0 home win courtesy of a Riyad Mahrez 40-minute strike, the corresponding fixture ended scoreless in Denmark.
The experience will stand the 27-year-old in good stead tomorrow, particularly as he is expected to once again go toe-to-toe with Leicester City talisman Jamie Vardy.
Zanka said: “You need to be on your toes and not switch off for a second.
“You have to be totally focused for the entirety of the game, if you give him half an inch then you are not going to catch him.”
The defender also went on to echo boss David Wagner’s sentiments that the Foxes’ current league position of 17th after a tough start to the new season, which has brought defeats to Arsenal, Manchester United and Chelsea, is to be ignored.
“They have had a very tough schedule,” said Zanka. “They are very hard to beat and are dangerous on the counters, when they win the ball in the centre they look to go long to Vardy.
“What they did to win the Premier League was a fairytale – everyone was rooting for them because it was such a one-off and it all came together in such a magical way.”