The cast have had plenty of other projects going on with Rob McElhenney directing a film based on 'Minecraft', Charlie Day was doing 'Pacific Rim: Uprising', Kaitlin Olson has her own sitcom called 'The Mick', Danny DeVito stars in Tim Burton's live-action remake of 'Dumbo' while Glenn Howerton has a sitcom with Patton Oswalt called 'A.P. Bio'.
In fact, there has been much speculation about whether Howerton, who plays Dennis, will appear in season 13 at all but the cast have since admitted that he will be in "pretty much every episode". In between times, they have come up with a couple of creative ways of replacing Dennis, as you will see in the trailer below.
The teaser also sees the show attempt to tackle the Time's Up movement (as only they could), and also shows Mindy Kaling's guest appearance.
Have a look below:
'It's Always Sunny in Philadelphia' returns on September 5 on FXX in the US and hopefully not too much longer after on Netflix over here.