Deep Keepers: April 19

We’re back with another edition of RotoGraphs’ Deep Keepers.

Paul Goldschmidt | 1B | Arizona
You have to love Goldschmidt’s debut numbers: .334/.408/.638 in 287 at-bats. However, he was playing in rookie ball. As a college-drafted prospect, he was probably playing against equal or lesser talent than he faced in Division I college ball. Bumped up to high-A ball in ’10, Goldschmidt has a 1.032 OPS in 11 games. Keep in mind, though, that the California League is a very good hitter’s league, so it’s going to skew his numbers. The 28 Ks in 47 at-bats is also a huge red flag; a strikeout rate of that level is not going to fly in the upper levels, so he has adjustments to make. With that said, you cannot ignore the success that he’s had so far. Monitor his progress.

Nick Weglarz | OF/1B | Cleveland
Weglarz fell off the prospect map a little bit last year after hitting .227/.377/.431 in double-A. On the plus side, his strikeout rate has shown signs of improvement over the past two seasons (it’s basically gone from very high to high), and his walk rate was an outstanding 17.6%. In fact, there is some thought that his patience is actually hurting him, as he’s letting too many hittable pitches go by. One of the big culprits behind his ’09 struggles was his BABIP, which was a crazy-low .245. Keeping in mind that Weglarz is still just 22, he has a lot of potential as an on-base machine with 20-25 homer potential. He’s currently hitting .321/.472/.679 back in double-A.

Jemile Weeks | 2B | Oakland
Weeks split the ’09 season between high-A and double-A but he began the year on the DL and may have never been truly 100%. An explosive, offensive-minded second baseman, Weeks is off to a hot start this season with a line of .342/.419/.579 in 10 games. He has the chance to hit for average and pretty good power (for a second baseman) at the MLB level. For him to truly reach his peek value, the former University of Miami star needs to start stealing bases again. A strong ’10 season by Weeks could convince the A’s to decline Mark Ellis‘ option to return for 2011.

Jordan Walden | RHP | Los Angeles (AL)
A move to the bullpen can do wonders for stalled pitching prospects. A top prospect as a starter, Walden struggled with staying healthy and with developing a reliable third pitch. Lacking pitching depth in the upper levels of the system, the organization chose to convert Walden to the ‘pen so he could focus on his heavy fastball and good slider. The early results have been good as he’s struck out seven batters in three double-A innings and has yet to allow a run. Relievers that can strike out batters and induce a significant number of ground balls can have a lot of success, and Walden looks like a future closer.

Nick Barnese | RHP | Tampa Bay
The pitching depth in Tampa Bay’s system is bordering on ridiculous and Barnese is yet another promising hurler who does not get quite as much ink as some of the other arms. He appeared in just 15 games in ’09 thanks to injuries but he posted a 3.43 FIP and allowed just 56 hits in 74.2 low-A innings. Moved up to high-A in 2010, the right-hander has given up just five hits in 13.1 innings and he’s struck out 10 batters with just two walks. Just 21, Barnese has a ceiling of a No. 2 or 3 starter. He could reach the Majors as soon as mid-2011, if he keeps pitching well.