On September 14th the New York Yankees promoted outfield prospect Mason Williams to the major league roster. Williams has been on prospect lists for years; let's take a look.
Williams was originally drafted by the Yankees in the fourth round in 2010 from high school in Winter Garden, Florida. His tools quickly moved him towards the top of Yankees prospect lists but his baseball skills were inconsistent; he had very strong 2011 and 2012 seasons but was less impressive in 2013 and especially in 2014, drawing criticism for his work ethic and having difficulty carrying his skills forward to the highest levels.
That changed in 2015 but with a caveat. From the 2016 Baseball Prospect Book:
Mason Williams, OF, New York Yankees
Bats: L Throws: R HT: 6-1 WT: 180 DOB: August 21, 1991
2011: Grade C+; 2012: Grade B; 2013: Grade B; 2014: Grade C+; 2015: Grade C
After floundering around for a couple of years, Mason Williams turned his career around last spring, or at least it looked that way. He hit .318/.397/.398 over 54 games in the high minors, was making a better effort on the field, got promoted to the majors and did not look out of place. Unfortunately he promptly hurt his shoulder after eight games and missed the rest of the season. Williams has always had the tools to be a solid player but given the circumstances it is hard to know if this was just a small sample size fluke or real, sustainable improvement. If he makes a full recovery, and if he avoids the makeup problems that have dogged his career, I think he profiles best as a fourth outfielder with defense, speed, and some on-base ability. I’m skeptical about his power. Grade C+.
Williams took most of the spring to recover from shoulder surgery and didn't get back on the field until July. In 43 games between rookie ball rehab, Double-A, and Triple-A with a composite .298/.315/.380 with 10 doubles, two triples, zero homers, six walks, and 26 strikeouts in 171 at-bats.
The basic contours here have not changed: Williams' best skills are on defense. He's a line drive hitter who posts good batting averages when he's going well but doesn't draw walks. He hasn't shown much power the last few years and I'm on record as being skeptical about his power. That said, it would not surprise me to see him show some more pop in his late 20s.
Injuries and focus have been his biggest concerns and those are the hardest things to project. Overall I still expect him to fit best as a fourth outfielder.