ID THE CORE

Here is the Cubs current roster:

ROTATION:

RHP Jake Arrieta

RHP Edwin Jackson

LHP Travis Wood

RHP Kyle Hendricks

LHP Tsuyoshi Wada

BULLPEN:

RHP Hector Rondon (closer)

LHP Wesley Wright

RHP Justin Grimm

RHP Brian Schlitter

RHP Carlos Villanueva

RHP Pedro Strop

LHP Chris Rusin

CATCHERS:

John Baker

Welington Castillo

INFIELDERS:

1B Anthony Rizzo

2B Arismendy Alcantara

SS Starlin Castro

3B Luis Valbuena

INF Chris Valaika
INF Javy Baez
OUTFIELDERS:
LF Chris Coghlan

CF Junior Lake

OF Ryan Sweeney

OF Justin Ruggiano

Objectively, which players will be part of the team during transition to competitve team and which players are CORE starters?

ROTATION: Arrieta, Jackson and Wood are going to be around for the next few years, but by the time the Cubs are competitive (maybe in 2018), they may not be still on the roster. Wada is a transition veteran pitcher. Perhaps Hendricks may be considered as a core rotation guy but he still needs to learn a steady out pitch since he does not have a dominate fast ball.

BULLPEN: Villaneuva, Schlitter, and Rusin are all AAAA guys holding a spot on a bad team. Strop and Grimm were acquired by the front office, but are replaceable as well as Wright. Maybe one could stay on as a bullpen specialist for the next few years. Rondon is being groomed as a closer so he appears to be potential core player.

CATCHER: Castillo is the core catcher by default since the Cubs organization had no catching depth until the draft. The Cubs paid a ton for Brave prospect Caratini so he may be the core catcher of the future.

INFIELDERS: The Cubs have used a vast collection of bench utility players to man the infield. Castro and Rizzo have been deemed core players for the future, however more and more Castro trade rumors will circle the press this off season. Alcantara started off fast but is returning to Earth, batting .255. He may be a transition player until Addison Russell and Javy Baez both hit the majors, for whom the front office has identified as core players.  Baez has arrived like the team savior, which is overhyped expectation. Valbuena and Valaika may be supersubs on a competitive team, likely not the Cubs down the road.

OUTFIELDERS: Not one outfielder listed is considered a core player.

So maybe, at best, there are 5 "core" players on the Cubs 25 man major league roster (20%).

This shows that there still is a long way to go in the competitive rebuilding process.