Uwe Rosler says he faces a "massive task" as manager of Championship side Wigan after being appointed last month.
"As a manager, you cannot have long-term plans. I have been given the task of taking the club back to the Premier League in 18 months.
"When you get relegated from the Premier League, expectations will always be high," he told BBC Sport.
The side have lost just twice in the German's first 10 games, and have progressed to the fourth round of the FA Cup, but they are only 11th in the Championship, five points outside the play-off places.
Rosler went close to promotion last season with previous club Brentford, who lost the League One play-off final to Yeovil.
He admitted it had been hard to leave the London club, but the chance to return to the North West, where he spent five seasons as a player for Manchester City during the 1990s, was too good to turn down.
"It was difficult for me to leave Brentford where I put something in place which is very sustainable for the next level," he said.
"There were different expectations there, but I am at a new club and you have to cope with that. There is a massive task, it is exciting."
The former East Germany international drew a parallel between his move to a bigger new club and David Moyes' switch from Everton to Manchester United.
Rosler - who described Moyes as a "great guy" - has had a less stressful start to his new job, but believes will succeed.
"I sympathise with David very much, he is a fantastic manager and will turn it around. It was a big task to take the job over after Sir Alex Ferguson," he added.
"It is the same for me, the person who takes over from Roberto Martinez has a massive task - and I am sure David will be alright and I am sure I will be alright."