The Calgary Stampeders have placed star running back Jon Cornish on the six-game injured list due to a concussion.

The league leader in rushing last year, Cornish suffered the injury when he was hit hard by Montreal Alouettes linebacker Kyries Hebert in the first week of the season.

The 29-year-old from New Westminster, B.C., was knocked out but did walk off the field on his own.

He will be eligible to return Sept. 6 when the Stamps play in Edmonton although the team has the right to activate him prior to that date if the situation allows.

Despite Cornish's absence, the Stampeders are 3-0 this season.

The teams says they want to ensure Cornish doesn't return to the field prematurely.