Trezeguet marked his full comeback with a goal set up by Amauri, silencing critics who said the two forwards could not form a partnership.
"There is absolutely no problem in them playing together," insisted Ranieri.
Mauro Camoranesi is also back from injury, but seemed very tired and could barely keep up with the Palermo players.
"Camoranesi has just returned and is not the player we all know, but he is improving. The only way he can gain match fitness is by playing.
"Recently we had been conceding too many goals and could not perform the right movement. The first thing I asked the lads was to see defence and midfield very close together and acting as a unit."
Ranieri added: "We played well against a tough opponent. The first half was exceptional from both sides, while in the second half we had good bursts of play, but should've dealt with the ball better, especially on counter-attacks."