Prowl

Prowl was quite tired after the last week, with a mountain of work to do that required quick resolution, and he didn't want to let Optimus down.
The Autobot rises from his perch and feels an unpleasant twitching in his circuits, especially in his lower back. He's not old, but he's not young either. So what's causing this pain? He won't go to the medic; his proud nature won't allow it. The bot isn't used to showing weakness.
Prowl feels a wave of irritation wash over him, hitting his processor like a whip. He's so fed up with it all. The Autobot thinks that if anyone disturbs him now, all his pent-up anger will spill out on this poor soul.