Scott Park admits Fulham face a summer-long battle to keep hold of their best players as he plots an immediate return to the Premier League.
Relegation to the Sky Bet Championship was confirmed on April 2 as a season that began with a £100million-plus recruitment drive ended in a 4-0 drubbing by Newcastle at Craven Cottage.
"When you're relegated you'll always be vulnerable to losing your best players. We will be no different," said Parker, who was named permanent boss last week.
"In saying that, the owners are committed to this team and have invested a lot of money into this team.
"I have no doubt they will be doing everything in their power to keep the best talent and best players so that gives us an opportunity next year.
"Of course I'd love Ryan Sessegnon to be at the club. Ryan fits into the bracket of a few others we want to keep. It's going to be a busy summer of rebuilding and us trying to keep hold of players.
"Harvey Elliot is definitely someone I believe in. In his 20 minutes against Newcastle you could see the talent he's got.
"He's a 16-year-old boy who is doing his GCSEs next week. He showed a lot of confidence."
A successful transfer window is just one of Parker's objectives this summer as he looks to make the changes that he insists are essential if Fulham are to recover from a dismal season.
"This season has given us a clear idea of what needs to be done at the football club," Parker said.
"This club needs a culture and an identity. We need those foundations for us to be successful. That's what we're going to do. There's a big challenge ahead.
"If we drive up standards and build culture, I suspect we'll have very successful seasons ahead.
"Standards at the football club need to go up and they need to rise across every department. It's possible to come back up next season.
"We know the league we are going into is very difficult. There are established Premier League teams in it who are struggling in mid-table.
"We understand the demands. But I've realised the only way we'll be successful is by building the foundations and establishing the culture. It's a big year ahead for us."
Jonjo Shelvey began the rout with a brilliant opener from outside the box, firing his first goal in over a year.
The midfielder's season has been interrupted by a thigh injury and he admits a challenging period could result in his future lying outside of St James' Park.
"I needed to put in a performance to get people talking back about me either at Newcastle – or away from Newcastle," Shelvey told NUFC TV.
"At least I've finished with a good performance and a goal. I'll enjoy the summer and see what the summer brings now. To be fair, I'm glad to see the back of this season."