The former France international believes that the Argentine spent the entire Champions League quarterfinal second leg "walking around the pitch."
The Argentine covered just 6.8 kilometres of ground in his side's 1-0 loss at the Vicente Calderon, half of match-winner Koke and only 1.4 km more than Barca keeper Jose Pinto, and spurned two clear-cut chances in the first half.
The former France international believes that the 26-year-old's performance was a sign of disrespect to the crowd and that he did not show enough urgency.
"[On Wednesday] Messi took people for idiots! He spent his time walking," he told beIN Sport.
Sagnol also took the time to praise Atleti coach Diego Simeone, saying he was a difficult opponent to face during his playing days.
"I had the chance to play against Simeone," he added. "He was a real dog on the pitch."