The fantasy baseball world waits impatiently for the arrivals of Anthony Rizzo and Wil Myers.  Some owners have been stashing one or the other on their rosters for months now, as folks like me keep spewing lines like “arrival is imminent” — whatever that means.  Truth is, these call-ups are utterly unpredictable.  They’re based more on opportunity than readiness, and “opportunity”, it seems, is defined differently by every GM in baseball.  Both Jed Hoyer and Dayton Moore are claiming patient approaches with their prospects, hinting that we won’t see either player in the majors this year.  But who can believe these guys?  Rizzo and Myers have combined for 55 homers on the season, and I’d love to see them join Trout and Harper in MLB’s 2012 prospect party.  When that might happen, though, is tough to gauge.  Until then, arrival is imminent.

Danny Hultzen | LHP, MarinersHultzen’s been Minor League Baseball’s most dominant pitcher over the past month, and at this point, the above blurb suffices for him too.  You can also include Trevor Bauer in that group.

Matt Barnes | RHP, Red Sox Barnes has responded well to his promotion to High-A,  posting a 1.37 ERA and a 0.89 WHIP, while whiffing 10.4 per 9.  It should be noted that Baseball America is calling his fastball “Verlander-esque.”

Miles Head | 3B, AthleticsThrough his last 10, Head is hitting .462/.512/.974 with 6 homers at Double-A Stockton.  Potential fantasy asset in a year or two as slugging CI.

A.J. Griffin | RHP, AthleticsGriffin has thrown back-to-back complete games at Triple-A Sacramento.  One of the games was official after seven innings, but still.  He’s been wonderfully efficient in what’s been a breakout 2012 for the 24-year-old.  Griffin is certainly a call-up candidate for the second half.

Marcell Ozuna | OF, MarlinsOzuna is known as a streaky hitter and he’s been reinforcing that perception recently.  In a two-game stretch earlier this week, the High-A outfielder blasted five homers and collected 12 RBI.

Trayce Thompson | OF, White SoxThompson’s power stroke is heating up as he’s collected 7 XBH (3 HR) through his last 38 PA at High-A.  The White Sox system is pretty ugly, but with his tremendous power-potential, Thompson is an exception.

Gerrit Cole | RHP, PiratesLast year’s top overall pick has been promoted to Double-A.  The 21-year-old out of UCLA posted solid numbers across the board at High-A, but nothing awe-inspiring in particular.  Still, Cole projects like a true ace and he’s now entered the realm of the high minor leagues.

Taijuan Walker | RHP, MarinersWalker is perhaps my favorite pitching prospect in the minors, but he’s been knocked around recently, allowing 13 ER through his last 13 IP at Double-A Jackson.  He’s just 19-years-old, so the struggles aren’t necessarily a surprise.  Walker projects as a fantasy superstar pitching out of Safeco.