Redknapp, in charge at Loftus Road since late last year, saw his side drop into the Championship after a goalless draw with Reading at the weekend.
The former Tottenham boss admitted a lack of time with the squad made it difficult for him to preserve their top-flight status.
And he was quick to point out there would be no easy path back to the Premier League with up to half the teams capable of challenging for the Championship title.
"Next year will be a big challenge as there are a lot of good teams and massive clubs in the Championship," he said.
"There are big clubs who have all been in the Premier League before and we are just one of them.
"There is a lot of hard work to be done this summer. It's a really good challenge, it's possible, but it's not going to be easy."
Bookmakers reacted to the development by installing Redknapp as favourite to be the next Premier League boss to leave his post with Sky Bet offering odds of 11/8 on the Londoner with Alan Pardew of Newcastle next in at 8/1.