In May 2012, Reading were taken over by Russian tycoon Anton Zingarevich,
who acquired 51% of the club,
and also announced a reshuffle in the boardroom.
Former Reading player and manager Mick Gooding
"I'm just hoping Reading don't end up in a similar situation Wolves find themselves. They sacked their manager before the end of last season, had an interim manager and this season they are near the bottom of the Championship.
"It's a big decision for the new owner to make and it will be an even bigger decision replacing him."
Reading struggled for the first half of this season, winning only two Premier League games, but they showed signs of improvement in 2013 with four successive victories in all competitions, including two in the top flight, and McDermott was named the January manager of the month.
Dropping out of the Premier League would mean the club would miss out on a share of a new TV deal worth about £5bn across three years from August.
The Reading statement added: "[Reading] owner Anton Zingarevich wishes to place on record his thanks to Brian who had achieved great success with the club since taking over as Manager in December 2009.
"Brian gained promotion to the Premier League last year for only the second time in the club's history thanks to a remarkable run at the end of last season.
"However, in our current situation, owner Anton Zingarevich felt that a change was necessary."
Reacting to the news, Reading striker
Noel Hunt wrote on Twitter:
"Want to say thanks to Brian for everything he did for me especially. He's been a great manager, man and friend to me and will be missed!"
Former Reading captain Aidy Williams added: "I'm very surprised, more by the timing than the actual events.
Reading player and BBC Radio 5 live pundit Jason Roberts
"I presume someone will be placed in caretaker charge and we will get on with it. It's a strange atmosphere.
"Players become conditioned to the revolving door. It's a tough thing to deal with. We had Brynjar Gunnarsson leave the other day and it was tough.
"From a player's point view we have to believe in what we have. Yes, you can look at it that we've not got much experience but you cannot say we're not good enough.
"We always had the belief, everyone would like more money but we have a genuine belief we can stay in the league."
"I'm disappointed. I've known Brian for well over 10 years. His pride will be dented, he's a very passionate football man and has done his apprenticeship. But he can hold his head up high.
"He won the Championship against all odds, but in all honesty he was fighting a losing battle with budgets."
Current Reading player and BBC Radio 5 live pundit Jason Roberts said: "I'm in shock and I'm sad because he brought me in. I'm disappointed for him, the players and the club.
"I'd like to put on record our thanks to the manager for what he achieved. He achieved so much.
"Our budget was nowhere near the top ten so for us to win the league was a massive achievement. With nine games to go we still have an opportunity and it's now time to take stock.
"As a player we have to just get behind the new manager, we all want the same thing - to stay in the Premier League."
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