Queens Park Rangers are set to lose a number of players in the summer transfer window.
The R's have been relegated from the top-flight and Crooks says that they will need to make wholesale changes if they are to get promoted next campaign, but he feels that Fer should be kept around.
The Dutch midfielder impressed Crooks with his performance against Newcastle United at the weekend, where he scored the winning goal in QPR's 2-1 victory.
"How QPR could have done with Leroy Fer during that crucial period before they were doomed to the Championship," he said.
"His second-half strike and all-round performance against Newcastle were brilliant. It will be very interesting to see whether Chris Ramsey can keep the Dutchman at Loftus Road and help the Hoops back into the Premier League. He's definitely one of the few players worth keeping."
Fer has largely impressed for QPR this season and there is no doubting his talent, but keeping him about could be difficult.
His power and technical ability makes him an appealing buy for teams in the Premier League and it could be a battle for QPR to make sure he stays with them.
If the London club can keep him it would be a signal of their intent and it would also give them a player to build their team around next term.
QPR are set to make a number of changes to their team in the coming months, but Chris Ramsey will have a player with genuine quality at his disposal if he is able to keep hold of Fer.