A tough day for the Chicago Bears' linebacker group. 

Just a couple of hours after the Bears' announced that Danny Trevathan was done for the season, they've now lost another one. 

The Bears announced that Khalil Mack is being placed on injured reserve and will have season ending foot surgery. 

Chicago has tried to give Mack some rest over the last couple of weeks hoping it would heal on it's own however it hasn't worked out. 

Mack has played in 7 games this year and registered 15 solo tackles along with 6 sacks and a fumble recovered. 

More details to come.