FIFA is reportedly planning to reduce the number of senior players who can be loaned out each season to eight.
According to SportBild (h/t Transfermarkt, via theMirror'sMark Jones), clubs will only be able to send out "eight professionals" at a time, though there will be no limits on loaning young players:
"Talents under the age of 21 who have been trained by their home club and have been under contract there for an extended period of time may continue to be borrowed in unlimited numbers to further their development by collecting match practice elsewhere.