Meanings of little niggle in English

I've had a little niggle in my left shoulder for a few weeks and have brushed it off as beginner's aches and pains.

Smith added that Dawson got the nod over Denly largely to cover for premier spinner Adil Rashid having a " little niggle".

Little niggles and worries will seem to crop up out of nowhere.

As for little niggles, I eventually extracted the following from Tom:

If he hadn't had a few little niggles, he'd have run before now.

It's easy to paper over the little niggles that arise when gaming as a family.

Up till now any little niggles they'd been suffering with could just have been shrugged off.

Colds, headaches, aching limbs, sore throat, indigestion; little niggling things which their powers found hard to banish.

For the first time in about eight weeks, I hadn't felt my groins or any other little niggles.

Cavanough said she had a few little niggling problems last time in, but no such worries this time around.

Robertson said there were " little niggles about transparency and tickets" but that LOCOG had done exceptionally well.

Again, little niggling in there.

Bravo Tango (3) is a talented horse on his day but a few little niggles have halted his progress.

I've gone into previous tournaments with little niggles or different things, but I've not missed a session this time. His advice for the younger players?