Lobaton is regarded as a strong defensive catcher that is especially adept at the art of receiving the baseball. He helped the Rays register a 3.74 team ERA, which ranked fifth in the American League, last season.
With the switch-hitting Lobaton as their starting catcher, the Rays went 46-30 (.605) in 2013 and claimed one of the American League's two Wild Card slots. Lobaton's .996 fielding percentage last year also established a new Rays single-season mark for catchers.
The 29-year-old Lobaton has 26 doubles, nine homers and 52 RBI in 191 career games with the Rays (2011-13) and Padres (2009), but is perhaps best known for hitting a game-ending homer in the bottom of the ninth inning of Game 3 of the ALDS vs. Boston. Lobaton's solo shot off Koji Uehara avoided a potential series sweep and extended the Rays' season.
The 22-year-old Vettleson was Tampa Bay's supplemental first-round selection, the 42nd overall pick, in the 2010 First-Year Player Draft out of Central Kitsap (WA) High School. In 314 professional games in the Rays system, Vettleson has batted .276 with 66 doubles, 15 triples 26 home runs, 171 RBI and 45 stolen bases.
Vettleson, who was recently rated by ESPN's Keith Law as Tampa Bay's No. 8 prospect, owns a strong outfield arm and has 39 outfield assists in three seasons as a pro. He was a Midwest League All-Star and team MVP after posting a .772 OPS and 20 stolen bases for Bowling Green in 2012.
The 22-year-old Rivero won a career-high nine games and posted a 3.40 ERA in 25 games/23 starts last season for Charlotte of the Single-A Florida State League. He is currently rated as the No. 10 prospect in the Rays' chain per FanGraphs.com. With a strong effort (8-8, 3.41 ERA, 27 games/21 starts for Bowling Green) in 2012, Rivero represented the Rays at the XM All-Star Futures Game at Kauffman Stadium and earned All-Star status from the Single-A Midwest League. His fastball regularly sits at 96 m.p.h.
Rivero is 29-25 with a 3.45 ERA in 96 games/65 starts in five seasons since signing with the Rays in 2008 as a non-drafted free agent out of Venezuela.
Karns, 26, went 0-1 with a 7.50 ERA in three starts for Washington last season in his big league debut. In his first exposure to Double-A, Karns finished 10-6 with a 3.26 ERA in 23 starts for Harrisburg in 2013. He was Washington's Minor League Pitcher of the Year in 2012.