The 19-year old has joined the Genoa-based club until the end of the season and Garrone is already looking for his presence to help lift the club.
"I am very happy that Macheda has chosen Sampdoria and I think it's the same for the fans," said Garrone.
"Macheda has easily filled the void left by Cassano, he will definitely do well.
"In these five months we will try to treat him well. With him here, the enthusiasm has increased tenfold."