Warbler?

Hi there, I’m trying to identify the little brown bird in these photos. Any help will be much appreciated. I was quite far away and zooming in on a small camera so it’s not sharp on detail. It was spotted on the edge of a garden in Scotland. The garden has woodland, but is surrounded by moorland and sheep grazing farmland. 

I’m quite new to bird ID and have looked through my books and tried the RSPB tool. Wondering if it’s a juvenile. Haven’t come up with any conclusive ID so hoping it’s familiar to someone.

Thanks in advance,