d'Arnaud suffered the injury while attempting to break up a double play during Monday night's game against Sacramento. d'Arnaud slid hard into second base and had an infielder fall on top of his knee, which caused the injury.
The 23-year-old was examined by Dr. Bernard Ong in Las Vegas, and the MRI results were later sent to Dr. Steve Mirabello in Florida who confirmed the original diagnosis.
"These cases are typically six to eight weeks, and at this point everybody, everybody being Dr. Mirabello and Dr. Ong, who examined him in Las Vegas [said] it is a non-surgical rehab," Blue Jays manager John Farrell said.
d'Arnaud, who is ranked the Blue Jays' No. 1 prospect according to MLB.com, was enjoying a productive season in the Pacific Coast League. He is hitting .333 with 16 home runs and 52 RBIs while posting a .975 OPS in 67 games this season.
The native of California wasn't expected to be considered for a promotion until the end of the season due to the presence of Blue Jays starting catcher J.P. Arencibia. d'Arnaud likely would have been a candidate when rosters expand in September, but it wasn't clear if that would still be the case.
d'Arnaud was acquired in a multiplayer trade for ace Roy Halladay following the 2009 season. Last season, d'Arnaud won the MVP award in the Eastern League following a breakout campaign with Double-A New Hampshire.