Peter O'Brien

O’Brien saw big-league action in September for the first time since 2016, and he played generally well over his 22-game stint. He flashed the impressive power that has long made speculators dream, hitting four homers with a .530 slugging percentage in 74 plate appearances. Strikeouts remained an issue (22 Ks, 35.3 K% for his career), but he at least put himself in position to contend for a roster spot in 2019. O’Brien is past prospect stage at this point and the swing and miss may be too great for him to overcome, but the Marlins aren't exactly stacked with first-base options, so it's not out of the question that O'Brien could break camp with a fairly steady role.

O'Brien flashed some power at the MLB level last season, but outside of the home runs, it was a disappointing season for the converted catcher. O'Brien posted a dismal .141/.179/.391 slash line in 64 at-bats and struck out a whopping 40.3 percent of the time. Five of his nine hits left the yard, but MLB pitchers were able to completely baffle O'Brien for the most part. Arizona decided he couldn't cut it behind the plate, so the organization shifted him to the outfield, but he was buried on the depth chart. In early January, they traded the fading prospect to the Royals. A return to catcher would obviously boost O'Brien's fantasy stock due to the shallow nature of the position, but that seems unlikely at this point, as he didn't catch a single game last season at any level, and KC has Salvador Perez. Despite the pitcher-friendliness of Kauffman Stadium, at least O'Brien may find a quicker path to relevance, and his power could play everywhere if it maxes out.

Where will O’Brien play? That’s the long-term question surrounding the slugging prospect, who made his MLB debut with Arizona last season though he only recorded 12 plate appearances in eight games. O’Brien has impressive power —- he belted 26 home runs in 534 plate appearances at Triple-A Reno last season, and he hit 34 homers in the minors in 2014. But at the start of 2015, O’Brien shifted from catcher to the outfield, catching just 11 games all season. O’Brien might not find regular playing time in a crowded Arizona outfield, and it’s been reported that he’s approached the organization about returning to catcher. If O’Brien can cut it as a big league catcher, his power at a sparse position will obviously be intriguing to fantasy owners. Keep an eye on this situation in the winter and into spring training.

The 24-year-old catching prospect was shipped to Arizona from the Yankees as the main returning piece in the Martin Prado trade. In 2014, he burst on the national prospect scene by belting 34 home runs in 427 plate appearances between High-A and Double-A. Catchers with 30-plus homer pop don’t typically show up in the big leagues, and O’Brien probably won’t be the guy to buck that trend. A .351 BABIP allowed him to hit .321 in 30 games at High-A, but upon his promotion to Double-A Trenton, he hit .245 in 72 games before getting traded. He also might not be able to stick behind the plate, as the Yankees had been trying him at first base before the trade, and would presumably have stuck with him at catcher if they thought he could handle it. He should reach Triple-A in short order, but it’s unlikely that he will hit enough for his power to continue to play up as he moves up the organizational ladder.