The value of preseason games will be up for debate again after what happened on Sunday.

According to NFL Network's Ian Rapoport, the initial diagnosis of Packers wide receiver Jordy Nelson's knee injury is a torn ACL.

It was a non-contact injury suffered during the Packers' preseason game against the Pittsburgh Steelers on Sunday.

[SHOP: Gear up Bears fans!]

Nelson, 30, has been Aaron Rodgers' top target over the past few years. In 2014, he recorded 98 catches for 1,519 yards and 13 touchdowns. 

The veteran receiver will reportedly undergo an MRI soon to confirm the initial diagnosis.

The Bears face the Packers at Soldier Field in Week 1 of the season. 

UPDATE: Here are some reactions from Bears players over the news of Nelson's knee injury.