First of all, I am in favor, but we need some rules here.
1) Loaned player should be max 5 stars. Not 6 stars, or even 7.
2) You can choice the amount of time of the loan. You can loan him for 1 week, 2 weeks, 3 weeks or 1 season. The max. amount of time is 1 season of course.
I'll think later about more improves for this suggestion.
Greetings, Pavel.