Oakland A’s prospect watch: Matt Milburn finding groove in High-A

The High-A Stockton Ports dominated the first half of the 2018 season, but they’ve seen most of their top stars move up to Double-A at this point in the summer. Nearly an entire rotation worth of starters (Luzardo, Shore, Dunshee, Howard), one of their best relievers (Romero), and half their lineup (Bolt, Heim, Mondou, Barrera) played so well they earned midseason promotions up to Midland (click here for more on those names).

Fortunately, a whole new wave of standouts is emerging in their place. Leading the charge is starting pitcher Matt Milburn, who has spent the last month dominating the league. The former 29th-round pick doesn’t have the prospect stock of the guys listed in that first paragraph, but he’s working his way into sleeper status with his recent performance. He finished June by throwing a full shutout against the Giants affiliate (rare in the lower minors), which helped earn him Cal League Pitcher of the Week honors. That began a string of five straight quality starts, three of them scoreless.

Milburn, last 5 starts: 1.01 ERA, 35⅔ ip, 29 Ks, 2 BB, 0 HR, 30 hits, 2.39 FIP

He’s averaging less than one run and less than one extra-base hit per start over that span, in a league known for being hitter-friendly. Stretch it out to his last seven starts, and his ERA is 1.50 with 38 Ks, 2 BB, and only six extra-base hits.

This isn’t the first interesting thing Milburn has done this year. In May he got a call to Triple-A Nashville to make a couple emergency spot starts, and in the second one he spun six scoreless innings. Upon his return to Stockton he got knocked around a couple times, but then began his current hot streak. His overall season numbers are suddenly looking pretty good.

Milburn, 2018 A+: 3.55 ERA, 96⅓ ip, 86 Ks, 11 BB, 8 HR, 110 hits, 3.41 FIP

That’s nearly eight strikeouts per walk, continuing a trend of strong K/BB rates throughout his career. After being drafted in 2016 he posted an absurd 44:2 rate between Rookie League and Low-A Vermont, and last season as a starter in Single-A Beloit he was well over four Ks per walk. Along the way he’s always given up more than his fair share of hits, just as he has this year, but lately he’s finding a way to turn his control of the strike zone into tangible run-prevention for the first time.

Of course, gaudy peripheral stats in the lower minors don’t guarantee anything on their own. Fellow K/BB monster Evan Manarino, also in the Ports rotation right now, is yet to find any success above Beloit — last year in Stockton he had a similar K/BB to what Milburn is doing now but still got torched, and he’s only been a little better this summer. It’s preferable to throw strikes and avoid handing out free baserunners, but if those strikes are too hittable then the whole package can prove underwhelming.

Is Milburn’s recent success a small-sample fluke, or the beginning of a breakout? As always we’ll have to wait to find out. At age 24 already, though, the right-hander will need to start moving up the ladder soon because he’s already on the older side for the lower minors.

Pimentel power

This is the third year in Stockton for slugger Sandber Pimentel. Injuries have gotten in the way the last couple seasons, with the most recent being a broken hamate in his hand, and he’s mostly fallen off the prospect radar since making the CPL in 2016. He’s generally hit well at every level, though, and at age 23 the book isn’t closed on him yet.

The big lefty returned to the lineup in late May and struggled for a few weeks, taking a month to knock his first homer. But toward the end of June he woke up, including back-to-back multi-homer games, and since then he’s been an absolute wrecking ball. His numbers since June 22, in 97 plate appearances:

Pimentel, last 23 gms: .313/.412/.771, 211 wRC+, 11 HR, 14.4% BB, 27.8% Ks

He’s averaging a dinger every other game, once every nine trips to the plate. His strikeouts are still high, but at least they’re back down under 30% during this stretch (still 34.1% for the season, along with an alarming 17% swinging-strike rate).

Like with Milburn, the next question is whether Pimentel has turned a corner or is just having a great month against younger competition. Either way, both players are helping keep the Ports on the winning side of things and it will be interesting to see how they fare if/when they get their own looks in the upper minors.

Draft sleeper

The first member of the 2018 draft class has arrived in full-season ball, but it wasn’t one we would have guessed. Outfielder Chase Calabuig, a 27th-rounder out of San Diego State, was called up on July 8 and has played every game since. It was unclear at the time whether the move was based on pure merit or short-term emergency roster need, but either way he’s making the most of the opportunity.

Calabuig, A+: 14-for-35, 6 doubles, 4 BB, 3 Ks

Put into percentages, those numbers look like this through 39 plate appearances:

Calabuig, A+: .400/.462/.571, 185 wRC+, 10.3% BB, 7.7% Ks

While it’s great that he’s hitting .400 through nine games, I’m not moved by batting average in such a small sample. Eventually a few more balls will find gloves and his average will come down. The thing catching my eye is that low strikeout rate, helped along by a microscopic 6.0% swinging-strike rate. He’s making about as much contact as a hitter can, and he’s turning it into line drives nearly a third of the time.

That contact rate isn’t coming out of nowhere, either. Over his four years in college he posted a modest 12.8% strikeout rate, and it dropped to 10.3% in his junior and senior seasons. It’s too early to draw any grand conclusions about the 22-year-old lefty, but color me intrigued.

Rest of roster

A few more notable names left in the lineup:

Persico, OF: .298/.358/.430, 115 wRC+, 3 HR, 8.8% BB, 16.6% Ks
Toffey, 3B: .248/.364/.399, 113 wRC+, 5 HR, 15.1% BB, 23.8% Ks
Blanco, OF: .291/.342/.406, 103 wRC+, 1 HR, 7.2% BB, 19.1% Ks

Both Luke Persico and Will Toffey lean more toward on-base skills than power, with Persico heavier on batting average (.325 last 50 games) and Toffey adept at walking. Dairon Blanco last played on July 4, but before that he put together a 15-game hitting streak in the second half of June and he still leads the club with 22 steals in 24 tries.

Sheehan: 3.86 ip, 39⅔ ip, 58 Ks, 22 BB, 1 HR, 3.20 FIP
Gilbert: 2.43 ERA, 40⅔ ip, 37 Ks, 14 BB, 1 HR, 3.44 FIP
Tomasovich: 2.92 ERA, 37 ip, 48 Ks, 23 BB, 1 HR, 3.63 FIP
Duno: 1.95 ERA, 50⅔ ip, 51 Ks, 15 BB, 4 HR, 3.64 FIP

Still tons of strikeouts in the bullpen, led by righty Sam Sheehan (34.1%). Fellow righty Angel Duno has put in an excellent showing in his first full season of relief, and lefties Will Gilbert and Andrew Tomasovich don’t have a lot in front of them on Oakland’s entire southpaw depth chart.

Wednesday’s games

Full slate of action.

Triple-A Nashville: LIVE, Chris Bassitt vs. Omaha
Double-A Midland: LIVE, Parker Dunshee vs. San Antonio
High-A Stockton: 7:10 p.m., Zack Erwin vs. Lancaster
Single-A Beloit: LIVE, Jean Ruiz vs. Bowling Green
Low-A Vermont: LIVE, Jose Mora vs. Staten Island

Bassitt gets his work in during the MLB All-Star break, and Dunshee looks to continue his strong first impression in the upper minors. Mora (age 20) walked five in as many innings but has been an interesting sleeper in Vermont so far, with a strikeout rate around 30%.

Link to box scores