Another brother of Ken, Cloyd, and Clete Boyer? Nope, not related.
Outfielder Bob Boyer appeared in the St. Louis Cardinals' spring camp as a non-roster invitee in 1959. It was quite a jump from the Class D level, but in 1958 he had hit 32 homers and 121 RBI with a .292 batting average for the Albany (GA) Cardinals.
The photo is from the St. Louis Post-Dispatch of April 15, 1959. It showed him sitting next to Ken Boyer, whom he had just gotten the pleasure of meeting.
http://www.baseball-reference.com/re...d=boyer-001rob