Both of these guys are considered to be top 10 prospects on the team, and many have both in the top 5. Both, however, have underperformed bigtime this year at their current levels.
Let's start with Stolmy. His ERA is a staggering 7.56, which is definitely a concern. But if you look at it closely, he's just getting hit, plain in simple. He has allowed 44 hits in 33.1 Innings, whereas he allowed less hits than IP in 2010. Well, LJ, how are you not worried, he's getting crushed! Well, on the positive side, he has a BB rate of 3.53 BB/9 innings, which is comparable to his 2010 mark of 2.95 BB/9 Innings. So what's with the difference in ERA and Hits. Simply, he's in AA, not high-A.
One can argue that the jump from high-A to AA is the biggest jump based on talent and experience. That is the point at which a pitcher can no longer use his stuff alone, he has to learn to pitch. That's all Stolmy needs to do: learn to pitch. He's 21, young for AA, so he has plenty of time to do it. I'd rather see him succeed right off the bat, but because of his low BB rate, and because of his age, I think it's just a learning-curve thing, and he will be able to do it.
As for Britton, he had somewhat low expectations coming in as a 23rd round pick. In 2008 and 2009, he threw only 45.1 innings before undergoing Tommy John surgery. His high-3s ERA was not bad for a 23rd round pick, but he racked up 23 walks in those 45.1 Innings, causing a 4.59 BB/9 Innings. As we all know, Britton recovered masterfully in 2010 with a 2.97 ERA in 75.2 Innings in Greenville. He only had 23 walks, giving him a sparkling 2.75 BB/9 Innings at Greenville. He has moved up to Salem this year, and he is certainly struggling. He has a 6.61 ERA with 20 BBs in 31.1 Innings. He, however, is struggling at Salem, a level that Stolmy crushed it in last year. While his 25 hits allowed aren't terrible, they certainly aren't dazzling. With Britton's stuff, he should be blowing High-A hitters away. His lack of control scares me. Aside from his 20 BBs, he must be leaving his pitches up. That's the only way a guy with a mid to high-90s fastball and 3 plus off-speed pitches is giving up almost a hit per inning in Salem.
Plus, the TJ surgery set back his development, he is 22 in Salem. Not dreadfully old, but not young for high-A. He really needs to figure out how to control his stuff. Britton could be dangerous if he can, but he will get rocked in AA next year if this continues. I would shut him down for a while a la Lackey, so he can get a fresh start. Maybe it's mental, maybe it's an injury. I haven't seen enough of his games to see definitively if his velocity is down (in the starts I watched it seemed fine, but velocity is always a concern for a struggling pitcher).
There is still a ton of hope for these guys. Stolmy should be a #2 or 3 starter in the bigs one day. He seems to have transitioned nicely in previous promotion, and every prospect is bound to hit a speed bump somewhere. As for Britton, he should be at least a great Lefty Set-up man, and could top out at a #1 or 2 starter, like Lester (who seems to be the logical comparison for this guy). But if Britton doesn't figure out the control, he may not make the bigs at all.
That's just my opinion, and I'd love to hear yours.