Edit: I posted this before I saw "wily mo"s fanpost series about relievers, so be sure to check those posts out too.
Since relievers are rarely mentioned on top prospect lists because they are so much lower on the radar than position players and starting pitchers, I realized I have no idea about prospects who are relievers.
Addison Reed has posted a 28.8K% with 10.6BB%. He has posted a solid contact rate of 76.8%, while relying on his 4-seam fastball, that has sat at 95 all season. Reed's command walks have been higher than one would expect after putting up fabulous walk rates in the minor leagues. Nonetheless, he still has closer stuff and will probably be the closer in Chicago very soon. Overall line- 4.41 ERA, 3.12 FIP, 4.23 xFIP.
Kelvin Herrera, on the other hand, has shown exceptional control, walking just 3.9% of batters faced, while K'ing 23.1% of them. His contact rate is a little bit better than Reed's at 74.5%, as he has been averaging 98.9(!) on his fastball thus far. Herrera has also run a really good 60.5% groundball rate this year, and has kept the flyballs to a minimum. This means that his current HR/9 of 1.33 is likely to come down. Overall- 3.33 ERA, 3.59 FIP, 2.66 xFIP.Since I really don't know a ton about prospects outside of the Mariners, especially with relievers, I'll just be posting about my favorite team, the Seattle Mariners, best relieving prospects.
Pryor has blasted onto the relieving scene, after dominating AA and getting moved up to AAA last month. Rumor has it, he might be on his way up to Seattle. If that is the case, it is deservedly so.
Originally drafted by the Texas Rangers (haha) in the 42nd round of the 2008 draft, Pryor was again picked, this time by the Mariners in the 5th round of the 2010 draft out of Tennessee Tech. He has cruised past the minor leagues in his two years, pumping his high 90's fastball and nasty slider by hitters, contributing to his K% of 39.8% in AA this year, and 32.6K% after being moved to AAA. He is obviously hard to hit, apparently touching 100 mph a few times this year.
Like most power pitchers, he struggles with his command at times. Pryor has a 16.3BB% in AAA this far, albeit small sample size. In his other years in the minors, his walk rate has hovered around 8-10%, so walks might be a problem for him in the majors.
Another problem for Pryor could be his amount of flyballs. Pryor and his 0.61 GO/AO ratio would mean he has a a ground-ball rate of 29% this year. Luckily, he'll be pitching in Safeco half the time, so home runs won't be as much as a problem. His HR/9 has been excellent in the minors though, as his only year above 0.00 was his 0.67 HR/9 in 2011.
Complete scouting report with video here: http://prospectinsider.com/view/a-look-at-stephen-pryor-/
Carter Capps was selected by the Mariners in the 3rd round of last years draft. A starting pitcher in college, the Mariners moved him to the bullpen this year, hoping to speed up his progression. Everything has worked this year, as he has been blowing hitters away in AA, with a 34.7K% to go along with a 5.1BB%.
Capps also works in the mid-to-upper 90's with his four-seam and two-seam fastball, having good command of both. He creates downward plane, keeping the ball on the ground to generate groundballs. Capps is also working on a slider, that flashes the potential of a true swing-and-miss pitch.
He'll need to figure out a pitch to get out lefty's if he wants to become a truly dominant major league closer.
His full-effort delivery is likely what kept the Mariners weary of keeping him as a starter, but Carter Capps should be up with the Mariners this year.
Originally a top prospect in the Milwaukee Brewers system, Wilhelmsen quit baseball after a couple of drug suspensions, preferring to travel the world and bartend, leading to his nickname "The Bartender". Six years later, Jack Zduriencik, former Milwaukee Brewers Scouting Director, signs Wilhelmsen to a minor league deal after the young man decides he wants to return to baseball.
Tom Wilhelmsen took just one season to make it to the majors. After initially struggling in the majors, back in 2011, he got sent down to AA to work back up as a starting pitcher. Still, nothing clicked, but he was called back up to the Mariners bullpen on August 8th. From then on, he finished the season as arguably the Mariners best reliever, holding opposing batters to a .175/.227/.250 line and running a KK/BB ratio of 22-to-4 in 23 innings. He seemed to have found his command, and was ready to step up in the set-up role next season.
He has impressed this year, pumping his upper-90's fastball and flashing the plus curveball. He has struck out 27% of batters faced, while walking 8.1%. Wilhelmsen figures to be the Mariners closer once Brandon League is dealt.
(Courtesy to Jeff Sullivan of Lookout Landing for these beautiful .gifs)
Originally drafted by the Milwaukee Brewers in the 21st round of the 2008 draft, Luetge was picked up by the Mariners in the Rule 5 Draft. He was thought as nothing more than a bad-LOOGY coming into Spring Training, with a minimal chance to make the team. Instead, he has been one of the Mariners more dominating situational relievers.
Working in the high-80's to low-90's, Luetge has been used primarily as a left-handed specialist, facing 31 left-handed-hitters while facing just 15 righ-handed-hitters.
Command has been a bit of a problem for Luetge so far, as he has walked 15.2% of batters faced. Nonetheless, his ERA is still 0.00, and he has been more than anybody should reasonably expect out of a Rule 5 Draft Pick.
So, my question to you is, who are your teams top relieving prospects that the majority of prospect followers have not heard of?