The 27-year-old joined the Red Devils in January of this year but has acted as cover for Edwin van der Sar and now new £18m signing David de Gea.
However, De Gea's first two appearances in a United shirt have come under scrutiny and Danish international Lindegaard has revealed that he is ready to be United's permanent keeper.
"I'm not scared about being number one," said Lindegaard. "That's why I came here - to play and be the best.
"It doesn't matter who cost what, the manager will make his decision on who plays in goal. I have no fear and I have belief in my own ability to perform at this level, otherwise I wouldn't be here.
"I'm proud to have created a debate over the goalkeeper position. But I want more than that."
Lindegaard cost United £3.5m from Danish League club Aalesund.