Going into this season, the Cubs had a major league roster than seemed fairly set in terms of what players would be around Chicago for most of the season. But with injuries minor injuries hitting players such as Jason Heyward, Jon Jay, Ben Zobrist, Addison Russell, and Brett Anderson, Theo & Co. has had to change route as we have seen a slew of call-ups from Iowa.

There have been a total of six prospects already getting the call for at least a short period of time so far this season starting with Felix Pena on May 5th. After the promotion of Pena to Chicago for a week, Rob Zastryzny, Dylan Floro, Jeimer Candelario, Ian Happ, and Pierce Johnson all got their calls.

So who is next? Now that the starting rotation is beginning to figure it out, big bats such as Kyle Schwarber are coming alive, and several guys are now able to flip back and forth between Iowa and Chicago, a new prospect might not need to be called upon until mid-season. When that time comes, who else could be just a call away?

There are three guys that currently call the Iowa outfield home and they are all but ready for a role in the big leagues in some capacity starting right this second. Mark Zagunis is the most polished of any player on the Iowa Cubs roster that has not already seen a glimpse of Chicago. While his batting average is not looking so hot (.232), that does not really matter after you look at every other offensive stat he has put up this year. His OBP/SLG/OPS slash line reads .394/.438/.832 and he is walking 18.3% of the time he comes up to the plate. Although his 23.2% strikeout rate this season is the highest of his career, his wRC+ has not been affected and still sits at 127. Better suited for the corner outfield positions, Zagunis also has the highest ceiling of any of the three current Iowa outfielders. Zagunis is not currently on the 40-man roster.

The other two outfielders waiting for their call to Wrigley are Bijan Rademacher and John Andreoli. With Rademacher in year two and Andreoli in year three in Des Moines, both guys have been biding their time and have continued to do what they do best. For Rademacher, that is to flat out hit. With a fairly low strikeout rate (19.4%) and a beautiful walk rate (14.6%) that are on par with his career averages, what you see is what you get with Bijan. Those plate discipline statistics paired with his ability to make solid contact and display a little pop can translate into a decent 4th or 5th outfielder for a team needing a fill-in for a few weeks.

John Andreoli could also make a decent fill-in player for the Cubs this year as a 5th outfielder and there is a good possibility that he will be a September call-up for the purpose of pinch running if nothing else. Speed is Andreoli’s strong suit as he charted 43 stolen bases last season. In fact, he has never stolen less than 17 stolen bases in a season since his first full professional season in which he swiped 55 bags. Besides the speed, Andreoli can play all three outfield positions. He walks at a very decent rate (13.6%) and displays surprising pop from time to time. The strikeout rate (31.8%) is a major concern, but his base running ability is what will get him the call to Chicago.

Victor Caratini is seemingly the official “next catcher up” for the Cubs this season. With the release of veteran catcher Carlos Corporan on May 2nd, Theo & Co. placed their faith in Caratini in case of an injury in Chicago. Part of the James Russel/Emilio Bonafacio trade, Caratini has a plus hit tool but not much power to speak of. His defense has been steadily improving as he has risen through the system. His AVG/OBP/SLG/OPS slash line is a very impressive .355/.393/.522/.915 with a wRC+ now up to 139. He has steadily cut down on his strikeout numbers over the course of his career and that number is now down to 12.7%. Don’t expect those numbers to stay quite that impressive though, as he has a BABIP of nearly .400 early in the season. For Caratini, his call hinges on an injury behind the plate in Chicago.

Strictly speaking in terms of the next possible call-up for pitchers, guys like Aaron Brooks, Jake Buchanan, and Jack Leathersich should be hitting your radar. But since we are focusing on prospects and each of those players have already exceeded their rookie limits, they are not considered for this or other Road to Wrigley pieces.

Between those non-prospects and the prospects that have already been called up this season, that does not leave many options for who might receive the next call. But looking at the 40-man roster is always a good decision. Prospects on the 40-man roster are already taking up a roster spot so no other move would be necessary to call those guys up.

Alec Mills is a lot like Eddie Butler in many regards. The still young and former top prospect needs some more seasoning in Iowa before getting his shot at the Cubs rotation in case of another injury. He has the best shot of anyone in Iowa in getting a call to the Chicago rotation. Mills’ ERA/FIP/WHIP slash line this season reads: 3.21/3.37/1.07 but in only 14 innings pitched because of an ankle injury that currently has him placed on the DL.

Jose Rosario is somewhat of an unknown for many people who keep up with Cubs baseball, which is strange because he has been in the system since 2008. Already on the 40-man roster, look for Rosario to be an option as a righty out of the bullpen if the combination of Grimm, Floro, and Johnson cannot get the job done in Chicago. Rosario is currently on the DL and has only thrown four innings this year so he would need a little more time back from injury before he could be ready for the call to the bigs.

While none of these players are making an aggressive push to send a player with a Major League job packing, each of the guys mentioned here is likely to get their opportunity this season in some capacity. The first step is getting that call but the next is to find a way to stick around the Friendly Confines.

In case you missed my introduction into Road to Wrigley, you can click on the link and read up on what the series is all about!

Greg Huss is currently a student at Ball State University in Indiana. Born and raised in Central Illinois, he spends far too much of his free time following the entire Cubs organization. You can follow him on Twitter here.