MELBOURNE midfielder Angus Brayshaw will miss the rest of the NAB Challenge with a left knee injury, but may still play in round one.

The 20-year-old hurt his knee in the opening seconds of last Saturday's pre-season game against Port Adelaide.

He now faces a race against time to be fit for the Demons' season opener against Greater Western Sydney at the MCG on March 26.

"Angus has suffered a low-grade medial ligament strain and some bone bruising on his left knee," Melbourne footy manager Josh Mahoney said.

"This will be treated conservatively, but we expect Angus to begin his running rehabilitation next week."

He was selected with the third pick in the 2014 NAB AFL Draft and finished fifth in the Rising Star voting last year.