CHICAGO -- From the Jose Abreu free-agent deal to trades acquiring Adam Eaton and Avisail Garcia, Rick Hahn has a strong resume in regard to deals made since taking over as White Sox general manager on Oct. 26, 2012.

For whatever reason, the three-year, $12 million contract agreed upon with infielder Jeff Keppinger in December 2012 does not fall on the positive side of Hahn's ledger.

That White Sox/Keppinger relationship all but came to a close Wednesday when the team returned Keppinger from an injury rehabilitation assignment with Double-A Birmingham, reinstated him from the 15-day disabled list and designated him for assignment.

"It didn't work," said Hahn of the Keppinger deal. "That's on me."

This Keppinger move made sense in the context of the White Sox coming off of an 85-win season in '12, when they sat atop the American League Central for 117 days. They needed a third baseman and didn't have one in their system who was healthy enough or reliable enough to fill an everyday role.

After hitting .325 over 418 plate appearances with the Rays in '12, Keppinger stood as one of the prime free-agent targets. The hope was to use Keppinger at third base but also all across the entire infield

Keppinger hit .202 with a .198 on-base percentage during his first April with the club and never really recovered. His season ended with a procedure that involved the debridement of the right shoulder, with the thought being that Keppinger would be healthy for Spring Training 2014.

Unfortunately, he wasn't. Hahn pointed out Wednesday that Keppinger basically had to restart his rehabilitation program in the middle of this past Spring Training and worked diligently in Glendale, Ariz., during extended spring camp and in Birmingham. He's healthy and ready to contribute at the Major League level, but in the reshaping process now featured by the White Sox, Keppinger no longer fits with the overall direction.

His final words as a member of the White Sox came via his Twitter account shortly after the team's announcement.

"So long Chi town. Wished I could've showed you I'm better than I played last season!!!" Keppinger wrote with an honest assessment of his .253 showing with four homers and 40 RBIs over 117 games last season.

"There was a brief conversation this morning, and he understood the rationale for it and we wished each other well," said Hahn of Keppinger's reaction. "It comes down to wanting to use plate appearances at the big league level for younger players we have."

Those younger players include Conor Gillaspie, who has taken over the primary starting job at third, and Gordon Beckham at second. It also includes top younger prospects such as Marcus Semien and Leury Garcia on the Major League roster as well as Micah Johnson and Carlos Sanchez on Triple-A Charlotte's roster.

Johnson, 23, was promoted to Charlotte on Tuesday. He swiped 84 bases overall last season between stops at Class A Kannapolis, Class A Advanced Winston-Salem and Birmingham and was named the 2013 Southern League Playoffs Most Valuable Player for the Barons, before hitting .329 with 10 stolen bases for Birmingham this season.

It will be up to Johnson through this next International League challenge to show the White Sox when he's ready for the Major Leagues.

"Good ones force the timeframe themselves," said Hahn of Johnson. "It might take a few months, it could take longer. Every development passes different."

Hahn said it was "conceivable" that the White Sox could explore a position change or changes for the middle infielders to fill other needs, but he added that while it hasn't been ruled out, "it's not in our plans." The White Sox certainly aren't going to move a player to a new environment and a new league and then ask him to learn a new position.

Development is key, which stands as one of the major reasons why Keppinger will not return. Hahn praised White Sox chairman Jerry Reinsdorf for allowing the team to make future decisions not based solely on economics, with Keppinger owed the remainder of $4 million for '14 and $4.5 million for '15.

"We are focusing on the future as opposed to trying to justify a decision from the past," Hahn said. "It's the price of doing business, and sometimes things aren't going to work out."