So as you've moved into the front corner to play a drop, the ball is now also in that front corner. So you'll need to keep you eye on it as you recover towards the T. You will need to cover the counter drop so you don't want to come back too far. If you come all the way back to the T and have to go back for the counter drop you will never make it as the ball is not in the air for very long!
So play your short drop and move 'bum' backwards to just in front of the T. That way you can cover the straight shot, the cross-court but also get back in for the counter drop that your opponent might play!