Macheda has failed to establish himself at Old Trafford after bursting onto the scene at the back end of the 2008/09 season with crucial goals against Aston Villa and Sunderland.
The Italian has not featured in the United side since last December and has been farmed out on loan to Sampdoria, QPR, Stuttgart in the last 18 months before linking up with Doncaster earlier this month.
The 22-year-old marked his full debut for Doncaster with two goals in the 2-2 draw with Nottingham Forest and he admits Paul Dickov played a big part in his decision to move to the Keepmoat Stadium.
"I'm not giving up on anything. I'm here to show everyone what I can do and who I am," Macheda told the Daily Star.
"I've got nothing to prove - except to myself. I want to enjoy myself playing football, then we will see in the future what happens."
Macheda added: The manager has been chasing me for a long time. I came here because of him and I wanted to thank him.
"It's thanks to him I have my confidence back. Hopefully I can stay until January."