Cape Town - Graeme Smith says it was disappointing to see his former team stumble to defeat against India in their ICC Champions Trophy encounter at The Oval on Sunday.
The Proteas had a solid start with a 76-run opening partnership between Quinton de Kock and Hashim Amla.
However, following the run-out of AB de Villiers, the Proteas collapsed from 140/2 to 191 all out.
"The side have been missing that spark, or that intensity to their play that characterises South Africa cricket," Smith wrote in his ICC column.
Smith, who is commentating during the ICC Champions Trophy, said that he could see the "panic creep" in the dressing room and out in the middle.
"The team's approach that has been the missing ingredient ... Since the team have started against England in May, it hasn't looked right to me as an observer," said Smith.
"Whereas I've grown so used to the free flowing, often powerful starts to our batting, on Sunday it was slightly timid and that led to a position where you could almost see a panic creep in to our play."
Despite the criticism, the former Proteas skipper believes that this squad is still one of the best the country has ever produced.
"I still believe this to be a wonderful short-form side, with very few - if any - weaknesses," said Smith.
"It just hasn't happened on the field, especially with the bat, and I know that those players will be hurting."
Smith, who led the Proteas in the 2004, 2006 and 2009 Champions Trophy tournaments, says that the team will learn from their mistakes going into the 2019 Cricket World Cup.
"I still care deeply about the environment that I spent so much time building as a player, and it hurt to see such an unrecognisable South Africa performance," said Smith.
"A disappointing tournament for any South Africa player or fan, but one from which valuable lessons can be, and have to be taken with the ICC Cricket World Cup 2019 to be played in the United Kingdom as well in less than two years."