The Royals are set to be deducted between six and nine points by the English Football League for breaching financial rules.
The Championship club are under embargo for breaching profit and sustainability regulations and just like Derby, are now in talks over agreeing a sanction that could drop them into the relegation zone.
On Wednesday, Derby were docked 12 points and dropped to the bottom of the Championship, six points off 23rd-placed Nottingham Forest.
Derby County are also in line to receive a points penalty for financial breaches.
And Madejski, who owned a majority stake in Reading for 22 years and gave his name to the club's stadium, has admitted he's 'extremely sad' with the impending sanction.
"What I'm deeply concerned about is how long the people that own the club want to engage," he told talkSPORT.
"They've put so much money into the club. They've built a magnificent training ground, state of the art.
"Unfortunately they have to stick by the rules, but you can't deny their eagerness for success."
Asked about what damage it could do to the club, he added: "I think it's extremely sad actually.
"I know the owners of the club are trying to get Reading into a good place, but you do have to adhere to the rules and regulations that are set out in the game.
"I'm afraid if you break those rules you have to suffer.
"It's tragic and I feel very sorry for the club and the fans. It's bad enough trying to get anywhere in football with a nine-point deduction.
"It's really quite devastating frankly."
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