Other rules changes.

[BlueInCanada]

Trade deadline moved to week 9 from week 8.

Coaches no longer need two successful challenges to get a third, after a single successful challenge they will receive the extra. 

QBs on the practice squad can be called up to QB3 in games, if the other two leave the game due to injury/ejection. The practice squad QB no longer needs to be signed from the practice squad the week after. 

The play clock expiring can be challenged. 

QBs down by contact, out of bounds before throwing a pass can be reviewed.