This is part-four of a ten-part series taking an in-depth look at when the top prospects in the game will reach the majors. For the rankings on this list, I used the Baseball Prospectus Top-101.
With a half-season in Double-A under his belt, the Twins have a choice with Rosario. They could start him back in New Britain to spend part of 2014 there or jump him directly to Triple-A. Of course, Rosario has a 50-game suspension to give the Twins time to make their decision, although it's not clear how that will affect it. I would guess that the suspension coupled with Rosario's struggles at the plate this winter would mean a trip back to Double-A when he's eligible again. He will probably see Triple-A by the end of the year and spend some additional time there next year before getting the call.
ETA: Summer 2015
What Could Speed It Up: An aggressive assignment upon return from suspension or general putrid-ness in the majors from the Twins.
What Could Slow It Down: If his struggles from the winter carry over into next season.
The Orioles need pitching help this season and have shown an aggressiveness with their pitching prospects recently, so it's certainly possible that we could see Rodriguez in Baltimore at some point this season. He already has a half-season of Double-A to his name and the Orioles have shown a willingness to jump prospects over Triple-A. Of course Rodirguez could use more time in the minors and a test in Triple-A, but if the Orioles need pitching help this season, he could get a call.
ETA: Fall 2014
What Could Speed It Up: If he starts the season in Triple-A or if the Orioles have injuries in the majors.
What Could Slow It Down: No need at the major league level.
Entering his first full minor league season, Shipley is probably destined for a return to Low-A South Bend, but as a collegiate pick, he probably won't stay there all year. He could split his time and end up in the California League, which would allow him to potentially start next season in Double-A. All of this hinges, of course, on his ability to pitch the way scouts believe he is capable.
ETA: Late 2015
What Could Speed It Up: As a college pitcher, he could easily hit the gound running and move quickly.
What Could Slow It Down: If the Diamondbacks are contending next season, they may not have room to call him up late in the year, pushing him back to 2016.
Ervin made a 12-game cameo in Low-A Dayton at the end of 2013 and should start the 2014 season there, but once he gets going, he could move quickly. A college bat, Ervin will be too talented for the low minors and should end the season in High-A, if not higher. That being said, the current Reds outfield doesn't have an opening. It could by the end of next season, however, and Ervin could be knocking on the door to full it. Most likely is that he joins the team sometime in 2016.
ETA: June 2016
What Could Speed It Up: Ervin exploded in short-season ball after signing and if he takes off like that to start the 2014 season he could get jump a level.
What Could Slow It Down: If he comes back to Earth and needs to spend more time at each A-ball level than expected.
Barnes is knocking on the door and will be in the Red Sox plans this season as starting pitching depth, somewhere in the 6-9 range if they end up having to use that many different guys in their rotation, which most teams do over the course of a full season. He'll spend the year at Triple-A Pawtucket, but should the Sox need a spot start or a long-term fill-in, Barnes will be in the discussion. Of course, the Red Sox rotation is deep, so Barnes could also spend the whole season in Pawtucket with an eye on next season.
ETA: Late 2014
What Could Speed It Up: Injuries to major league starters.
What Could Slow It Down: No openings in the big leagues or if the Red Sox don't trust a rookie to start in a playoff race.
Peterson's bat looks to be the real deal and he's poised to move quickly through the Mariners farm system. The Mariners, on the other hand, have desperately promoted prospects in an attempt to save front office jobs. That shouldn't affect Peterson too much, as he's still to far from the majors to rush for job-saving purposes, but I would expect him to move as quickly as possible. His .922 OPS in 26 Low-A games may be enough for the Mariners to start him in the California League where Peterson could put up some crazy numbers.
ETA: Late 2015
What Could Speed It Up: That's a pretty aggressive estimate, so getting him to the majors faster than that would require something pretty crazy.
What Could Slow It Down: If he starts in Low-A again this year and ends in the California League, he could still need the entire 2015 season between Double and Triple-A.
The 2012 first round pick has already reached Double-A and spent 49 games there last season, but even if he's ready for another challenge, where's he going to go from there. The Cardinals don't even have room in the majors for top outfield prospect Oscar Taveras so they certainly don't have room for Piscotty - and that's not a knock on Piscotty. There's no reason to rush him because there's no where for him to go, so I'd expect Piscotty to stay in Double-A until Taveras opens up a spot for him in Memphis. He won't be in the majors until there's room for him.
ETA: Summer 2015
What Could Speed It Up: Injuries that open up a spot.
What Could Slow It Down: The same thing that's slowing down Taveras - strong veteran players in the majors.
The White Sox have already said that their fifth starter spot this season is Johnson's to lose this spring, so that takes most of the excitement out of this discussion.
ETA: Spring 2014
What Could Speed It Up: Faster than that?
What Could Slow It Down: It would take a truly horrible spring.
68. James Paxton, LHP, Seattle Mariners
The Mariners haven't come out and handed Paxton a starting spot publically like the White Sox did with Johnson, but we can all do the math. If the Mariners want to contend this season they need Paxton to be ready. He made four starts last season so there's no reason he won't be.
ETA: Spring 2014
What Could Speed It Up: See Johnson, Erik.
What Could Slow It Down: See Johnson, Erik.
69. Henry Owens, LHP, Boston Red Sox
Owens is on the same path I described above for fellow Red Sox prospect Matt Barnes, but he's one year behind. Owens will spend most of 2015 in Double-A, and if all goes well, you can take Barnes' description and use it for Owens next season. It'll save me the work.
ETA: Late 2015
What Could Speed It Up: If the Red Sox ran into some serious pitching injuries, they could consider reaching down to Double-A for Owens.
What Could Slow It Down: A slip up in the upper minors