The North African side defeated tournament debutants Madagascar 3-0 in their quarter-final, while the Teranga Lions had to make do with a 1-0 success against Benin.
The experienced French coach was in charge of the West Africans between 2013 and 2015, but he believes the encounter will be decided by what pans out on the pitch.
"If the match came down to knowledge of the players that would be a good thing, but the reality is different," Giresse said at his pre-match press conference.
"Knowledge and relationships are one thing but what happens on the pitch is the most important."
Furthermore, the Frenchman expects a tough game against Aliou Cisse’s troops, and is wary of the threat of talisman Sadio Mane.
“Senegal are a strong team and they're different from any other team. They have Sadio Mane, whom I predicted a great future for before. But, we'll be ready,” added Giresse.
"We did everything to qualify and we're happy with everything.
"I won't answer any criticism, we're in the semifinal. It's not constructive.”
Tunisia are aspiring to reach their fourth Afcon final against Senegal.
The Eagles of Carthage won the 2004 edition on home soil, after defeating Sunday’s opponents 1-0 in the quarter-final, on the road to their only Afcon title.