When out cycling I prefer not to carry it on my person*, but in a side pocket of a 1950s Karrimor of Rawtenstall heavy duty cotton duck saddlebag. Said side pocket also includes spare innertube. So, bit concerned about possible damage to the screen and the three lenses on the back of the phone. The majority of 'sleeves' seem to only fit bare phones. However this German gang came up on a search offering custom made sleeves - simply measure the phone's circumference with its protective cover.
It arrived today in orange and black leather
(other options available), from Germany without hassle and on initial inspection seems to be ACE 
https://www.fitbag.com/
* In case I ever come a cropper and fall off. The phone is only carried for emergencies and taking occasional photos - would never answer the thing if it rang, or need it to hand otherwise.