Statistics as of May 31 courtesy of Baseball-Reference.com and MILB.com. Ages listed are "season age," meaning age they'll be at end of season. View our May 1 installment here.
1. Lucas Giolito (age 21): Giolito's overall numbers so far this season might not seem so inspiring for the top prospect in the system and top right-handed pitcher prospect in the game. In 48 1/3 innings for AA-Harrisburg he's 3-2 with a 3.17 ERA, 1.448 WHIP, 7.8 K/9 and 5.o BB/9. The walk number, especially, is concerning. In his outing on Monday, Giolito gave up one earned run on three hits and six Ks, but that came with four walks. His previous two starts, though, he allowed three walks with 11 strikeouts combined in 12 innings, so he's still refining his command. Giolito had some insightful things to say about his control in this interview. With no place to put him in the rotation, don't expect him any time soon -- unless injury rears its ugly head in the Nats rotation.
2. Trea Turner (age 22): Turner has nothing more to learn in the minor leagues. In 190 plate appearances at AAA-Syracuse he's slashing .321/.385/.489 with 13 doubles, five triples, three home runs, 24 RBIs and 16/16 stolen bases. His career minor league averages: .322/.384/.462. Look how similar they are. He's ready. While he doesn't possess the arm at short of Danny Espinosa, very few do. He's got enough range to stay at the position and any offset in defense will be more than made up for at the plate once the Nats inject him into the daily lineup. If the Nats plan to use him at all this season, they need to call him up now to get him acclimated before they get into the stretch run. It's a trickle-down effect: Turner pushes Espinosa (.199/.297/.622) to the bench and most likely Stephen Drew (.157/.214/.508) out of a job.
3. Victor Robles (age 19): Robles slowed a little in May compared to his white-hot April (.351/.474/.545), but overall he's still doing impressive things in his first season of full-season ball age just 19. He's slashing .319/.415/.481 in 192 plate appearances for Low-A Hagerstown with five homers, 23 RBIs and 14/20 stolen bases. He's just 7 of 30 in his last 10 games, and he's struck out 14 times compared to two walks in the last month. Those hoping for a mid-season promotion to Potomac are probably reaching a bit, but there's no panic, and there's no need to rush. Robles has an exciting skill-set and he's just getting started showing it off.
4. Reynaldo Lopez (age 22): Lopez' start on Sunday is what has everyone in the Nats organization drooling over him: five hits and no walks with 12 strikeouts in just five innings. Unfortunately, the previous start was just as discouraging: four earned on four hits and five walks with just four Ks in 5 1/3 innings. Such is life for a 22-year-old still learning to harness his stuff. Overall, Lopez is pitching to a 4.15 ERA and 1.259 WHIP with a 10.6 K/9 and 3.8 BB/9. He's given up seven homers in 47 2/3 innings and owns a 1-4 record.
5. A.J. Cole (age 24): Cole has made 10 starts for Syracuse and they've been, well, meh. In 49 2/3 innings he's 4-2 and owns a 4.89 ERA and 1.490 WHIP, with 7.4 K/9 and 2.9 BB/9. He's also giving up 10.5 H/9 (.284 average against), which speaks to the inflated WHIP. He had a game back in April where he allowed eight earned runs, so that skews things, but only once in four May starts did he allow fewer than three earned runs and he's only had two of his 10 starts where he's struck out more than base hits allowed. He's certainly not dominating Triple-A. Heck, he's barely just okay right now.
6. Erick Fedde (age 22): On May 15, after Fedde gave up five earned run on seven hits and a walk -- with just two Ks -- in five innings, his ERA for the season stood at 6.62. But something seemed to click for him as the two starts since, the righty has been superb. In his last 11 innings he's given up no earned runs on seven hits and one walk, with 11 strikeouts. Overall, his record stands at 3-3 for High-A Potomac, with a 5.00 ERA, 1.267 WHIP, 9.2 K/9 and 2.0 WHIP. There's something worth waiting for here. This is his first full season in his return from Tommy John surgery after 14 starts last year.
7. Wilmer Difo (age 24): Where did you go, Wilmer Difo? He looked like a budding star in 2014, but a disappointing follow-up last year has turned into an unmitigated disaster season so far this year. In 208 plate appearances, the not-really-young-anymore second baseman is slashing .227/.309/.265 for AA-Harrisburg with six total extra-base hits, none of which were homers. He does have 19/22 stolen bases, so he's running well, but this little contact at Double-A is troubling -- and he leads the Senators with 10 errors as well. Hope he enjoyed his cup of coffee last year.
8. Anderson Franco (age 18): Has yet to make 2016 debut, most likely slated for short-season A Auburn in the New York-Penn league, which opens June 17. Hit .269/.346/.389 with four homers, 21 walks, 28 strikeouts in 193 at-bats between GCL and NY-P. At 6-foot-3, 190 lbs, he should grow into the frame and some scouts think he'll develop 20-homer power, already drawing comparisons to the Phillies' Maikel Franco (no relation).
9. Austin Voth (age 23): Voth is doing what he always does: put up good minor league stats. He's 3-2 with a 2.81 ERA, 1.071 WHIP, 8.8 K/9 and 1.4 BB/9 in 51 1/3 innings for Syracuse. Last time out, on Saturday, Voth featured his third best pitch -- a changeup -- a little more and had tremendous success, allowing just three hits and no walks against six strikeouts over seven innings. In five of his nine starts he hasn't allowed a run. Voth's a guy that doesn't really do anything all that special -- except have success.
10. Andrew Stevenson (age 22): Stevenson's average has dipped a little bit in May, but his OBP and slugging hasn't, so it's probably just a little regression, since he hit .341 in April. Overall, the speedy outfielder is slashing .309/.361/.426 in 207 plate appearances for Potomac with nine doubles, five triples, one homer and 16/25 stolen bases. He'll have to improve on reading pitchers to improve his steal rate, but his defense has been sublime as advertised.
OF Brian Goodwin (25, AAA): 191 PA, .292/.354/.444, 4 HR, 27 RBI, 6/6 SB, 17 BB/44 K.
C Pedro Severino (22, AAA): .124 PA, .265/.285/.342, 1 HR, 11 RBI, 1/1 SB, 3 BB/15 K.
RHP Trevor Gott (23, AAA): 26.1 IP, 3-1, 3.42 ERA, 1.443 WHIP, 3.8 BB/9, 6.2 K/9.
MI Chris Bostick (23, AA): 197 PA, .295/.354/.426, 2 HR, 19 RBI, 5/11 SB, 14 BB/27 K.
OF Rafael Bautista (23, AA): 216 PA, .257/.355/.311, 1 HR, 12 RBI, 26/29 SB, 25 BB/32 K.
C Spencer Kieboom (25, AA): 126 PA, .266/.336/.376, 2 HR, 15 RBI, 0/0 SB, 11 BB/24 K.
2B Osvaldo Abreu (21, A+): 196 PA, .240/.323/.333, 2 HR, 16 RBI, 9/13 SB, 20 BB/42 K.
1B Jose Marmolejos-Dias (23, A+): 207 PA, .257/.372/.497, 7 HR, 23 RBI, 1/4 SB, 30 BB/48 K.
3B Drew Ward (21, A+): 174 PA, .313/.408/.567, 8 HR, 22 RBI, 0/1 SB, 21 BB/46 K.
3B Kelvin Gutierrez (21, A-): 209 PA, .304/.340/.403, 1 HR, 27 RBI, 9/11 SB, 13 BB/33 K.
SS Max Schrock (21, A-): 209 PA, .311/.368/.421, 2 HR, 21 RBI, 13.15 SB, 16 BB/18 K.
C Jakson Reetz (20, A-): 115 PA, .227/.386/.386, 2 HR, 13 RBI, 1/1 SB, 19 BB/25 K.
OF Rhett Wiseman (22, A-): 168 PA, .250/.269/.267, 4 HR, 29 RBI, 2/4 SB, 14 BB/35 K.
RHP Andrew Lee (22, A-): 10 starts, 46.2 IP, 2-2, 3.66 ERA, 1.221 WHIP, 3.1 BB/9, 7.9 K/9.
RHP Jefry Rodriguez (22, A-): 10 starts, 50.1 IP, 5-2, 2.86 ERA, 1.073 WHIP, 3.0 BB/9, 7.2 K/9.
RHP Mariano Rivera (22, A-): 14 games, 25.1 IP, 3-0, 2.49 ERA, 1,224 WHIP, 2.5 BB/9, 6.0 K/9.