Williams Perez - SP, ATL
In four starts since joining the Braves rotation in mid-May, Perez has been outstanding. There's a good chance that the owners in your fantasy league haven't taken notice, but perhaps you should.
Perez was not a big-name prospect prior to being called up for the first time this year. Signed out of Venezuela as a teenager, he has never appeared on national top prospect lists despite solid numbers throughout his minor-league career (30-23, 3.32 ERA in seven seasons).
That might be why his strong performance since joining the big-league ranks has largely flown under the radar. Perez was called up last month after going 2-0 with a 1.33 ERA in five starts at Triple-A, and after making a couple relief appearances he joined the Atlanta rotation, where he has a 2.35 ERA in four turns.
The righty has been tallying strikeouts at a solid rate (24 in 25.1 innings), but his biggest strength has been inducing grounders. His 54.1 GB% would rank as the seventh-highest in the NL if he had enough innings to qualify.
This attribute has helped Perez limit damage in a big way. Although he has allowed nearly a hit per inning on average as a starter, only two of those 23 hits have gone for extra bases -- one double and one homer. When opponents are generally getting only one base at a time, it becomes pretty tough to manufacture the big inning.
Between the high volume of grounders and strikeouts, Perez has a good recipe for sustained success, along with a secure spot in the Atlanta rotation. He's owned in only 2 percent of Yahoo! leagues.
Vince Velasquez - SP, HOU
The Houston Astros mean business. After years of scuffling, they're off to a tremendous start that has them leading the AL West. Now, they're taking full advantage of a potent prospect pipeline to continually reinforce the big-league roster.
Over the weekend, we learned that the Astros were bringing up shortstop Carlos Correa, the top prospect in baseball. On Monday, we learned that they're also promoting another of their best young talents in Velasquez. He replaces Roberto Hernandez in the Houston rotation.
The 23-year-old right-hander has been a strikeout machine in the minors, averaging 10.8 K/9 over five seasons. He's been especially dominant over the last two seasons, fanning 91 hitters in 63 innings in 2013, and 37 in 26 innings at Double-A this year prior to the promotion.
Along with the big K totals, Velasquez has been extremely effective overall at Class-AA Corpus Christi, which is why Houston elected to promote him even though his five starts there represent the totality of his experience above Single-A. He was 3-0 with a 1.37 ERA, having allowed just 15 hits and one homer in his 26 innings of work.
That's the kind of flat-out domination that should have deep-league owners lining up to add this exciting young hurler. Obviously he's got some big question marks attached due to his lack of experience, his mediocre walk rates and his jump straight from Double-A to the bigs, but he has some of the best stuff fo any pitcher in the minors so he's a gamble with huge upside.