Manchester - Manchester United manager Louis van Gaal admitted Friday his job might not be safe if his side lost many more games.
Van Gaal, speaking on the eve of Norwich City's visit to Old Trafford, expressed his surprise at the sacking Thursday of Jose Mourinho - who previously worked under the Dutchman at Barcelona - by Chelsea.
But Van Gaal, a title winner in Spain, Germany and the Netherlands, acknowledged that any manager can be vulnerable in modern-day football and knows results could also determine his long-term future at United.
Also read: Mourinho sacked as Chelsea manager
Van Gaal said: "What I can say, it (Mourinho's departure) was a big surprise for me, I didn't expect that that.
"He is a fantastic manager with a record that nobody has in this football world.
"But it is still possible. The main thing is always, of course, the results and second the chemistry between the players and the manager and his staff.
"I cannot judge what was happening at Chelsea but I was very surprised."
Van Gaal, who insisted that contrary to some reports of dressing room disquiet the chemistry between himself and his players remains fine, added: "I have the full confidence of my board and my players, I feel.
"But we have to get results, we have to win, we know that - the players know it, I know it and my staff know it.
"We have to win because when you lose too much it's the end of the world for me also."
Van Gaal's position at United has come under increased scrutiny from supporters, pundits and ex-players following a five-match winless run which has seen United slip to fourth place in the Premier League and go out of the Champions League.
United have lost their last two games and four of their last six home fixtures have ended in 0-0 draws, with Van Gaal admitting the supporters need to be be won over again.
He said: "It's always like that when you lose, fans have to prove their belief again.
"The board of directors can see what you can do as a manger in practice but the fans cannot see that, so when you lose you need the belief of the fans and that is a question of the fans not the manager to answer."
United's recent run has seen them slip six points behind Premier League leaders Leicester City and they can not afford to let further points slip at home to struggling Norwich on Saturday.
The return of captain Wayne Rooney following a three-match absence with an ankle injury will increase their attacking options with Van Gaal hoping the England striker is back to his best.
He added: "You see players coming back more fresh because they haven't played such a heavy game.
"I hope when he plays he scores a goal because it is a big day for him because it's his 500th game. Not too many players have reached that record."
As well as the return of Rooney, midfielder Ander Herrera is expected to return to the squad after missing five games with a hamstring injury.
Phil Jones and Morgan Schneiderlin could also start after being on the bench for last Saturday's defeat at Bournemouth but Bastian Schweinsteiger serves the second game of a three-match ban.