A promotion worth noting: Switch-hitting infielder Jesus Guzman was bumped up from Double-A to Triple-A Sacramento and has started the past two games at third for the River Cats. Guzman, 24, signed in November as a free agent from the Mariners’ organization. He busted out for 25 homers and 112 RBI in Single-A ball in 2007 after not posting double-digit HR totals in any of his first six professional seasons. He began this season on a tear in Double-A and was hitting .359 with 13 homers and 69 RBI when he was promoted. The A’s are trying to find a third base prospect to groom for the future, so surely the front office is watching Guzman closely.