Confirming speculation, San Diego Padres starter Luis Perdomo was optioned Thursday to Triple-A El Paso. Right-handed reliever Kirby Yates (ankle) will be activated from the disabled list Friday. Perdomo had struggled mightily in four starts to a 8.36 ERA and 2.50 WHIP. The Padres haven't announced Perdomo's replacement, but might stick with starter/reliever Robbie Erlin and considered promoting prospect Eric Lauer. Meanwhile, Yates was sporting a shiny 0.00 ERA and 0.55 [...]