Manchester United suffered a humiliating 3-0 defeat at the hands of local rivals Manchester City at Old Trafford on Sunday.
The home side failed to lay a glove on the reigning champions as Pep Guardiola’s men strolled to a victory against a team who have looked nowhere close to the side that finished third in the Premier League last season.
Key admitted that he was harsh to write off Ten Hag last year but insisted that he has been proven that he was right about his assessment of the Dutchman.
He insisted that it is now clear that Manchester United are not moving forward under the current manager and it is no longer a question of if but when he gets sacked by the Premier League giants.
The veteran broadcaster wrote on his blog: “Ok. When I called him Erik ten Months it was a little bit harsh, but it was an obvious one wasn’t it? And after the weekend capitulation to City – by far the worst Premier League derby performance by any United team – I might not be too far out.
“I haven’t got anything else to add about the derby.
“It seems as though everybody has now caught up with what I’ve been saying for months so what’s the point?
“The only question left is how long has ten Hag got?”
Manchester United are sitting eighth in the Premier League standings, eight points behind the top four spots.