I believe the above Yantz photo depicts him in a 1914 Cleveland Bearcats (American Association) uniform. That would be consistent with the markings on the back of the photo, and the insignia on the cap. I found a newspaper article which indicated that a catcher Yantz was with the Bearcats at the beginning of the 1914 season, and then in May he went to Portland of the Pacific Coast League. The Portland part would be consistent with George Yantz' record at Baseball-reference.com. Perhaps he was with Cleveland for too few games to merit a citation.
The article also indicated that the catcher Yantz was with the Toledo club of the American Association in 1913, which was transformed into the Cleveland club the following year. Baseball-reference.com has George Yantz with New Orleans in 1913, but for only 44 games, so he certainly could have joined Toledo later in the season.
George Yantz Minor Leagues Statistics & History | Baseball-Reference.com
P.S. An article in a Louisville paper makes clear that the 1914 player with Cleveland was George Yantz and that he hailed from Louisville. This Louisville article cited George Yantz' appearance for Cleveland against Louisville in a game on April 19.