There's always one isn't there? In this case it appears to be Arthur Cowell, on the extreme right. I've checked other Rovers pictures from the era and there doesn't appear to have been a tradition for one of the jerseys to have been in contrast to the others, so maybe Cowell just has his top on back to front?
The players pictured are: Miles Chadwick, Arnie Whittaker, Bob Crompton, Sammy McClure, Adam Bowman, Willie McIver, Tinker Davies, Fred Pentland, Sam Wolstenholme, Billy Bradshaw & Arthur Cowell.
I first saw this picture on https://twitter.com/footballmemorys
