Dest left Ajax for Barca a fortnight ago - but only after the Catalans failed with a bid for Aarons.
The unnamed agent told the Athletic: "There is one who suffered, it is Max Aarons.
"There was interest from Barcelona, but Norwich was unwilling to do anything if their price wasn't met.
"Barcelona have left and signed Sergino Dest. But if Aarons has a good eight or nine weeks, someone else will come for him in January."