The standout pitcher on the day was 22-year-old right-hander Victor Diaz . Diaz’s numbers with Greenville this year—a 3.88 ERA and 1.49 WHIP with 25 walks to 63 strikeouts in 60 1/3 innings—do not really stand out, particularly considering his age. But even though he is already 22, he is relatively new to pro ball having only signed when he was 20 years old. Looking further into his season, however, reveals bad performances in the first half of the season leading to a 6.59 ERA and 1.78 WHIP in his first 28 2/3 innings with 12 walks and 23 strikeouts. But in the second half, Diaz put up a 1.42 ERA and 1.23 WHIP in 31 2/3 innings with 40 strikeouts and 13 walks. Furthermore, to end the year, Diaz did not allow a run in 16 2/3 innings over August and September, striking out 25 hitters and allowing only 8 hits and 9 walks.In his inning of work, Diaz struck out the side, showing off not only his impressive fastball but improved secondary stuff and the ability to locate when he is locked in. Diaz is listed at 6-foot-3, 190 pounds, but looks heavier than that. He is filled out and has a sturdy pitcher’s frame with minimal projection remaining. Because of his size, he does have effort in his delivery and a lot of moving parts. As a result, Diaz has struggled in the past to lock into his three-quarters arm slot at times, but in this outing, he was repeating his delivery well. Diaz works exclusively from the stretch and sat at 99 mph for every fastball he threw. The pitch has late life and showed bat-missing ability, eliciting two swing-and-misses against right-handers. If he can harness his command and stay within himself like he did in this outing, the pitch has elite potential and is easily one of the best fastballs in the system. The more encouraging aspect of this outing was that his secondary pitches both flashed at least average, with his slider flashing above-average-to-plus. When he feels his slider like he did in this outing it is brutal on hitters, coming in 91-93 mph with 10-to-4 break and short, hard bite. He got two swing-and-misses with the pitch and two strikeouts, showing the ability to both bury the pitch down and away from right-handers and throw it for a strike and freeze the hitter. Diaz also threw a few 90-92 mph changeups. The change is behind his slider, and he slightly slowed his arm down on some, but the pitch did show drop and elicited two swing-and-misses as well.Diaz is one of the more intriguing bullpen arms in the Red Sox system. His stuff has always been electric, but he seems to have made significant strides this season and the confidence he gained from his late-season success carried over to this outing. Given his shaky command profile, he will likely always be susceptible to a blow-up outing, but having shown the ability to keep the ball in the park (only two home runs allowed in his career, spanning 93 innings) and on the ground (posting a 2.57 groundball to fly ball ratio this year), he may be able to minimize the damage from any command lapses. There is definitely still risk, but the upside is there for a potential late-inning reliever.-----Left-hander Robby Sexton , the club’s 14th-round pick this June, got the start, throwing two innings and striking out five. In six starts in the Gulf Coast League, the left-hander was dominant—as one might hope a college draftee would be in the GCL—allowing just 4 runs over 20 innings in six starts, striking out 23 while walking just one.Sexton has a sturdy, filled-out pitcher’s frame, listed at 6-foot-0, 225 pounds and showing minimal projection. He starts on the first base side of the rubber and throws from a three-quarters arm slot, utilizing a high leg kick and slight trunk twist before coming forward. His fastball sat 88-90 mph, topping out at 91 mph, with natural cut. The pitch jumped on hitters thanks to deception in his delivery from keeping the ball behind his body. He did a good job locating the pitch, as one might expect from his numbers, and had hitters fooled, getting four strikeouts with it, three looking. With his command and movement, the pitch has average potential and could be especially effective against left-handed hitters.Sexton complimented his fastball with a changeup and breaking ball. His changeup is more advanced at this point. He has advanced feel for the pitch, throwing it with deceptive arm speed, the same as his fastball. He threw it 82-83 mph, and the pitch showed drop when he turned it over down in the zone. His breaking ball was on the slurvy side at 76-80 mph. The pitch had two-plane break, but tended to roll to the plate at lower velocities. At the upper end of that velocity range, it showed some bite and looked more like a slider. The pitch needs some refinement, but if he can consistently throw the harder version, it has the potential to be a decent alternative to his other two pitches to give hitters another look.Long term, Sexton’s future lies in the bullpen. Given the demand for left-handed relievers, especially those who excel against hitters on the same side, he is someone that bears watching next season as he makes his first foray into full season ball.-----Another reliever on the first day was the Red Sox 25th-round pick in June out of Allen County Community College, right-hander Francisco Lopez-Soto . Lopez-Soto who signed for just a $40,000 bonus, had a nondescript professional debut, allowing 9 runs on 12 hits and 8 walks in 12 innings over nine appearances while notching six strikeouts. Listed at 6-foot-5, 225 pounds, Lopez-Soto has a solid pitcher’s frame and some projection remaining. He throws from a low three-quarters arm slot and has a jerky delivery with an inconsistent release. He came across his body at times and struggled to repeat his delivery. While his mechanics and arm slot will be tough on right-handers, left-handers get a very good look at the ball. His fastball sat 92-94 mph and he mixed in a long, loopy 11-to-5 curveball at 72-75 mph, a horizontal slider at 84 mph, and a firm changeup at 84 mph. All of his secondary offerings need refinement, and given his arm slot, focusing on the slider would make the most sense, but he did not show much feel for it in this outing.-----Drafted as a catcher, Jordan Weems never showed enough ability offensively to stick, even after a move to first base to start this season. After hitting .119 in 22 games for Portland to start his age 23 season, Weems was sent back to extended spring training to convert to pitching. Weems showed some ability in eight Gulf Coast League appearances, allowing just 6 hits, 4 walks, and a hit batter over 17 innings, only giving up 2 runs but striking out just 10. After a promotion to Short-Season A Lowell, the strikeouts went up, as he tallied 20 in 15 2/3 innings, but he also allowed 19 hits and 8 walks as 12 runners crossed the plate.In his outing on Friday, Weems showed off a strong arm, but also that he has a long way to go. Weems has an athletic pitcher’s frame and a quick, live arm. He has a short arm action with some effort, including a head whack in his delivery. His fastball sat 92-94 mph, but it is on the straight side and is hittable as a result. He throws his changeup 80-83 mph with deceptive arm speed. It will flash fade down and away from a left-handed hitter, and he has some feel for it, but it is inconsistent. He throws his curveball 71-73 mph with long 12-to-6 break, but he does not snap that pitch off consistently either.