R.J. Alvarez

Alvarez, a third-round pick by the Angels in 2012, got off to an unbelievable start with Double-A Arkansas last season, allowing 13 hits and just one earned run while fanning 38 in 27 innings (0.33 ERA). Seeking immediate, back-end bullpen help, the Angels included Alvarez in the package to San Diego that yielded closer Huston Street, and while Alvarez wasn't quite as successful in his 17 outings with the Padres' Double-A San Antonio affiliate (2.76 ERA), he maintained a strikeout rate of 12.7 K/9 while trimming his walk rate nearly in half (from 3.3 BB/9 with Arkansas to 1.7 BB/9). It was enough to earn the right-hander a September callup, and though he issued five free passes in eight innings with the big club, he allowed just three hits and one run. Alvarez complements a mid-90s fastball with a slider and a changeup -- the kind of stuff that could put him in the setup mix to begin 2015, and gives him a chance to eventually become a closer. Traded to Oakland in December, Alvarez will push for a spot on the A's Opening Day roster during spring training.

The Angels' first pick in the 2012 draft (third round), Alvarez turned heads at High-A Inland Empire last season when he struck out 79 batters in 48.2 innings pitched. Perhaps equally impressive, he allowed only two home runs in the hitter-friendly environment of the California League. Alvarez, who will likely begin the season in Double-A Arkansas, is expected to move quickly through the Angels' minor league system, and has an outside chance of appearing with the big club at some point in 2014.