The former Black Leopards mentor had been tasked with assisting Swallows to prepare for the first leg encounter in Mbabane on Sunday.
Reports from Swaziland are that Rautmann was involved in nasty scuffle with Swallows' Malian coach Alou Bandara on Tuesday during the team's training session at the Somhlolo Stadium.
The former Moroka Swallows coach confirms to KickOff.com last night that he was back in the country and had left Swaziland because of the poor relationship with Bandara.
"I couldn't continue working in such unbearable conditions. I was only asked to help the club for the game against SuperSport, but the man seemed to think that his job was in jeopardy and made things difficult for me continue working at the club."
Swallows general manager Sandile 'Beyond 2000' Zwane also confirms to KickOff.com that Rautmann had left.
"Yes, it is true that Walter has left the club but we are still awaiting an official report from the manager to establish what happened between the two coaches.
"It is really sad for us to lose a coach like Walter Rautmann whom our players had grown to love. He has installed sense of belief and confidence among the players ahead of the game against SuperSport United.
"For him to leave us just before the game against SuperSport United makes the situation even worse."