Any ideas?

Hey, I have a Volkswagen Up! 1.0 3 cylinder.
Recently I’ve noticed what I thought was a slight shudder through the clutch pedal at low speeds/when it was pressed in. And then I felt it (not as much) without the clutch depressed at low speeds. But it is more noticeable when holding down the clutch. This isn’t all the time, it’s just when I’m putting the clutch down to come to a stop. I’ve had a look underneath and I can’t see anything obvious moving about or any obvious leaks.
There is a protective metal piece that has fallen off inside the front bumper I thought it could be like that but then again that wouldont explain the shudder through the clutch pedal and I’m sure that’s always been like that.
HELP please?
Any ideas?