Bristol Rovers manager John Ward believes his second spell at the struggling League Two club will be the hardest task of his career.
Ward previously managed the Pirates from 1993 and 1996 and was reappointed on Monday until the end of the season following the sacking of Mark McGhee.
"It's the toughest thing I've done," the 61-year-old told BBC Points West.
"When I first came here we were struggling, but it was a three-year deal and it was about building."
He added: "There's no time now - I've got to rebuild a team in four days."
Ward left Rovers 16 years ago with the club in Division Two, having guided them to a top-half finish in every year in charge, and reaching the play-offs in 1995.
He went on to join cross-city rivals Bristol City before spells with Wolves, Cheltenham, Carlisle and most recently Colchester, who dismissed him in September.
Rovers are in the relegation zone and only two points off the bottom of the Football League. Saturday's 4-1 defeat by York, their ninth loss in 11 games, prompted the club to part company with McGhee, who had been in the role for almost a year.
Ward will be the eighth person in seven years to take charge at the Memorial Stadium and he has urged the Gas fans to get behind the players and management staff.
"Whether up or down, win, lose or draw, we need to pull together for the sake of this football club," he continued.
"I've got an excitement about coming here and trying to resurrect this club in to a position of safety.
"I come here in the blue and white colours and hope that the fans, the staff and especially the players respond in the same manner.
"I know the supporters here well - certainly the older ones - and they will go with that. They want a team that will wear their colours with pride.
"I can't make false promises, we're just going to try and do our very best. They've seen that from me before some years ago.
"The younger guys behind the goal, who make all the noise and get behind the team, are probably wondering who I am and what I do but hopefully the elders will tell them that this guy is OK.
"If we do it together and succeed together then this club progresses and that's what we've got to make sure of."