Fulham still managed to scrape a 1-1 draw thanks to another Chelsea loanee, Lucas Piazon, who played for the Royals in 2015/16.
But Kalas’s blunder follows a high-profile gaffe against Reading in last season's Championship play-off semi-final second leg, when his handball led to the winning penalty for Jaap Stam's side.
Fulham boss Slavisa Jokanovic did little to defend his centre-back after the game.
“It happened so far from my position that I didn’t really see it," said the Serbian. "The referee was very close to the situation when he made his decision. It’s too early in the season to start complaining about the referees and blaming them.”
Judge for yourselves with the benefit of video...
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