The player's FanGraphs articles are going to open when you click on the player's name in bold with their stats and advanced metrics. The stats that you see throughout are accurate as of June 10, 2015 if you're living in the US. Here's my top 10.
The Giants made a rather surprising move, promoting Arroyo to High A this season instead of bringing him back to Augusta. Early on, Arroyo has been proving that he's up to the challenge, hitting with a hot bat before an oblique injury sidelined him for 6 weeks and returned when DrB checked out Tyler Beede's start if I am not mistaken then his bat cooled off a bit. Most of his success comes from him trying not to be a power hitter, instead, he's focusing on squaring the ball up, and getting base hits and getting on base (Full article located here) and it paid off, raising his OPS while maintaining a solid batting average (His average is higher before his injury and is easier to fluctuate because of the fewer games that he played this season). He's also been aggressive at the plate, drawing a 1:4 BB/K ratio and he hasn't stolen or tried to steal yet. That said, I say his hit tool is legit and I could even grade that at 60 if his bat gets hotter late in the season and the Giants should slowly develop the guy.
4. Adalberto Mejia LHP (AA)
Mejia started this season serving a 50 game suspension after testing positive for sibutramine, a weight loss drug to aid treatment of obesity along with diet and exercise. In 2014, Mejia is a mess with a 4.67 ERA, more hits than innings pitched, less than 7 K/9, plus the addition of the suspension. The only positive that I can take from him last year is that his BB/9 is still consistently below 3. I am starting to think that the issues last year are due to weight issues and I think he's served that suspension well. In his return from his suspension, he is back with a bang with 4 no-hit innings with a walk and 3 strikeouts and based on an MiLB article, his composure is better than ever and he looked confident on the mound, another positive sign with a good fastball and a plus change and average curve. With last year now in the rear view mirrors, I am expecting more great things from Mejia this season. I may have put him too high but it's all positive so far with another prospect sinking.
5. Kyle Crick RHP (AA)
Now if you think that this is too low for Crick, I might be wrong but this is the highest point that I can project him in my top 10. If Bickford's here, he'll be higher than Crick on my top 10. He's been consistently inconsistent since the season started and possibly throughout his career, having his longest outing sandwich between short starts with high pitch counts. His walk rate is actually higher this season with 7.51 BB/9 while he's at 6.08 last year and his K/9 is down from 11 to 9 this year. He got some mechanical issues (imbalance in leg kick, east-west finish), speculations of mental issues starting to arise, and other more together with his walk issues. The only good news is that the walks and the high pitch counts doesn't bit him hard in the butt due to his plus stuff, with an LOB% of a whopping 87%. That's some high-end reliever stuff right there and that's where I'm projecting him right now. Age is still his friend but unfortunately, time is slowly running out for him. (I'll discuss more about Crick's issues and why I am pessimistic about him pretty soon.)
6. Steven Okert LHP (AAA)
I place Okert right here based on the value that he can give to the Giants out of the bullpen as a potential heir to the throne of Affeldt and Lopez. Even though his ERA might make you think that he's pitching poorly this season, I'll tell you that he got 3 really bad outings especially that 5-run outing where he didn't record an out. The golden nugget lies on how he fared versus lefties this season and so far in 11.1 IP against lefties, he allowed 7 hits, 4 BB, 4 ER, and 19 Ks with hitters batting .175 and that's how I'll evaluate him as he got 2 above-average pitches to build with. So far, he's been good on that. He needs to resolve his current problems against righties but he'll most definitely be a September call-up because he's a good asset to have with being only a LOOGY as the worst-case scenario. He got one foot inside the Show.
10. Ty Blach LHP (AAA)
10 notable prospects outside the Top 10 in no particular order