Nottingham Forest boss Steve Cotterill lambasted the Football League's decision to reduce the number of substitutes from seven to five.
Football League clubs voted to change the number of replacements before the start of this season as many teams were struggling to fill their full complement of substitutes.
"It is one of the worst rules ever, I cannot understand it," he told the Nottingham Post. "It has obviously been done for financial reasons.
"That is fine if it needs to be done lower down, in League One and Two. But I am not so sure that works in the Championship.
"Some clubs in the Championship are bigger than some in the Premier League."