Dylan Bronn’s own goal into extra time shattered the North Africans’ ambition of reaching the final after Ferjani Sassi wasted a penalty to defeat Senegal.
Giresse’s men face Nigeria in Wednesday’s third-place encounter.
“Our target was more than just reaching the semi-final. But now we focus on the game against Nigeria and hope to win third place,” Giresse told the media during Tuesday’s pre-match conference.
“I believe this is going to be a psychologically tough encounter because we are not over that defeat from Senegal yet.
“I cannot say all our players are fit after playing two extra-times but we will do our best.
“This is football and we understand the whole team disappointment. But we have to forget that and focus on the Nigeria game.”
Tunisia have won only one of their three third-place games in Afcon history. That triumph was a 3-0 win over Uganda in 1962.