On Wednesday, Cisse released his 23-man squad for the 2019 Africa Cup of Nations (Afcon) leaving out the 26-year-old attacker as well as Lorient midfielder Sidy Sarr.
Sada was preferred ahead of Ngom, who spent last season on loan with French Ligue 2 side Nancy where he managed to score two goals in 14 league games.
Sada, meanwhile, was a consistent performer for Bernard Blaquart’s men as they ended the 2018/19 season in 9th spot on the Ligue 1 table, where he scored three goals in as many appearances.
He went on to deliver convincing displays during the Terenga Lions’ 10-day training camp, which earned him a spot in the final squad.
"I decided to choose Sada because of his aggressiveness. The fact that he also plays in the first division and he also had a very good season with Nimes played a part,” Cisse told FootSenegal.
“I did not know that Santy Ngom would leave, but what we saw, indeed, during these 10 days there I estimate that Sada deserves to stay with us. It was in the last minute that I decided that Sidy and Santy were going to leave.
“It was difficult as a choice, they both deserve to be in the team, the difference was small. I took them to my room, to have a chat. But overall, they understood well. The difference in this new generation is that they prefer overall interest [rather] than their individual interests.
"Santy is a talented boy that I went to look for two years ago. Many people have asked questions. But as soon as they saw him play, they saw that he is a player who has many qualities. A lefty, able to do very good things but at this level also when you have Sadio Mané, Diao Balde Keita, Ismaila Sarr, the competition is tough. These are difficult and complicated choices.”
The Terenga Lions will lock horns with three-time African Champions Nigeria in their final preparatory game before the tournament on Sunday.
The 2002 runners-up will open their campaign in the continental tournament against the Taifa Stars on Sunday, June 23.