Spence, a 24-year-old left-hander from Australia, has pitched parts of two seasons as a reliever for the San Diego Padres. In 2011, he had a 2.73 ERA in 29.2 innings, following that up with a 4.35 figure this past year in only 10.1 innings. In his 40 career innings, he has 41 strikeouts. The middle reliever has upside, having only reached triple-A ball this past year after being promoted straight from double-A, where he had a 1.71 ERA in 2011.
Herndon has appeared in 94 games over the past three seasons for the Philadelphia Phillies, posting a 3.85 ERA. The 27 year old underwent Tommy John surgery in June that ended his season. In October, the Phillies desginated him for assignment and he was picked up by the Toronto Blue Jays, but just a few weeks later, the Blue Jays cut him as well and now he will be with the Yankees.