West Bromwich Albion were the latest top-flight side to make a move for the Italian youngster but he is now braced for a move back to his homeland.
Macheda is likely to join Sampdoria until the end of the season after experiencing limited opportunities at Old Trafford.
On the move? Manchester United striker Federico Macheda
His agent Giovanni Bia told Sky Italia: 'Sampdoria? We are nearly there. We are awaiting only the formality of exchanging faxes.
'It's a six-month loan, then we'll see with if he can stay another year. It's a 99 per cent chance he'll have to return to United.'
Heading off: Macheda has been backed to shine in Italy
Sampdoria are in need of a new forward with Antonio Cassano joining AC Milan, while Macheda - who left Lazio for United in 2007 - is lookingto play more regularly.
Club president Riccardo Garrone said: '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.'
Macheda, 19, was an instant hit at United when he scored an injury-time winner on his debut against Aston Villa in April 2009.
The news Macheda is set for Serie A will dash any hopes West Brom had of securing his services.
Baggies boss Roberto Di Matteo admitted: 'Macheda is someone we looked at right at the start of last season. He's a striker, we are after a striker and we have to look at whether Manchester United will let him join us.'
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