Cech posted on Instagram after Łukasz Fabiański's penalty save in West Ham's 2-1 victory over Leeds United was invalidated after the Polish goalkeeper was judged to be off his line.
Leeds' Mateusz Klich scored the re-taken penalty.
"How is any goalkeeper supposed to cover an area of 7m and 32cm by 2m and 44cm without any foot movement while the players shoot from 12 yards with (an) average speed of 70 mph which takes the ball 0.35 seconds to cross the goal line is beyond my understanding..." Cech, clearly adept at calculations and forms of measurement, posted.
And the 2012 Champions League winner didn't stop there, calling for a change in the rules.
"It is easy to criticise without giving any solution so here it is : CAN THE REFEREE JUST MAKE A SECOND LINE 4 FEET FROM THE GOAL LINE USING THE SPRAY AND THE PENALTY HAS TO BE SAVED IN BETWEEN?"
Cech's initial statement "without any foot movement" isn't quite correct.
According to Law 14 of IFAB's Laws of the Game, "The defending goalkeeper must remain on the goal line, facing the kicker, between the goalposts, without touching the goalposts, crossbar or goal net, until the ball has been kicked."
"When the ball is kicked, the defending goalkeeper must have at least part of one-foot touching, or in line with, the goal line."
A 'keeper can move their feet, as long as at least one is on the goal line.
