Francesco Guidolin warned Palermo he will set aside “sentiment” for after the game, as Udinese come to town.
The tactician had several spells on the Rosanero bench from 2004 to 2008 and a fractious rapport with President Maurizio Zamparini.
It was Guidolin who took Palermo into Serie A and now he could send them back down to Serie B.
“There will be time for sentiment after the game,” he said in his Press conference.
“I was very happy in Palermo and met marvellous people as well as achieving good results on the field.
“However, tomorrow there is a very important match. Let us set aside tension and those trying to stir up trouble. We will enter a fiery atmosphere, but the game is on the pitch and we have to focus only on that.”
Udinese are battling for a Europa League spot, but are without the suspended Maurizio Domizzi, Danilo and Giampiero Pinzi, while Andrea Lazzari is injured.
Guidolin has therefore given youth team defender Tom Siku his first senior call-up.
Udinese squad for Palermo: Brkic, Padelli, Pawlowski; Angella, Basta, Benatia, Heurtaux, Gabriel Silva, Pasquale, Siku; Allan, Badu, Campos Toro, Faraoni, Merkel, Pereyra, Rodriguez; Di Natale, Maicosuel, Muriel, Ranegie, Zielinski