ARLINGTON -- The A's youth movement expanded on Wednesday, with infield prospect Chad Pinder joining the club in Texas.
The middle infielder, ranked by MLBPipeline.com as the organization's No. 9 prospect, was a second-round Draft pick of the A's in 2013 and has steadily climbed the ladder, graduating to a new level each year. He's batting .258 with a .310 on-base percentage to go along with 14 home runs and 51 RBIs in 107 games for Triple-A Nashville.
Infielder Tyler Ladendorf was placed on the 15-day disabled list with a sprained left wrist, opening up a roster spot for Pinder.
Pinder, 24, was drafted as a second baseman, but he has spent the balance of the season manning shortstop for the Sounds. He also has experience at third base.
The A's are likely to play him mostly at second, though Pinder will have the opportunity to take over at shortstop temporarily when everyday man Marcus Semien goes on the paternity list within the next week.
The A's have been in full youth mode as the season wears down, as they try to figure out which pieces can help them mold a future contender. Ryon Healy has taken over everyday duties at third base, while Jake Smolinski and Brett Eibner have been clocking several games in the outfield.
Pinder's callup prompted a well-deserved promotion for the club's No. 4 prospect, Matt Chapman, who has been transferred from Double-A Midland to Triple-A. The slugging third baseman, who went to the A's in the first round in 2014, smashed 29 home runs at the Double-A level, after totaling 23 the year before at Class A Advanced Stockton.
• Left-hander Sean Doolittle allowed one hit and struck out one in one inning on Monday in his first rehab outing with Triple-A Nashville. He will throw another inning for the Sounds on Thursday and is expected to make three total appearances before returning, A's manager Bob Melvin said.
• Right-hander Henderson Alvarez (shoulder) threw from flat ground Monday, meaning he's close to throwing off a mound.
Jane Lee has covered the A's for MLB.com since 2010. Follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.