Kakuta has joined Lazio on loan to the end of the season.
Reja said: "I just ask the fans to give us a hand. Why did the players turn us down? I am just a Coach, so I work with the team I am given. There are regrets the players did not accept the transfer, but I can't do anything about that.
"Kakuta is a left-sided player who can play in the front three and behind the centre-forward. Stefano Mauri will be back too and he can take any of the attacking roles."