The boss was frustrated by the attitude and dissent shown towards officials by several players in last month's friendly defeat in Montenegro. Strikers Martin Paterson, inset, and Kyle Lafferty also picked up needless bookings in the 2-0 loss in Podgorica.
Worthington said: "We've had a pep talk on discipline and it was a simple message - behave yourself on and off the pitch. If you don't, I'll take action. Discipline in the last campaign was outstanding. Maybe some individuals dropped their guard a little bit in Montenegro but that's not how we work. Distractions won't be allowed to get in the way of what we want to do in this campaign."