• MLB's No. 1 prospect highlights stacked AFL rosters
The power-hitting Chapman was promoted to Triple-A Nashville last month after totaling 29 home runs and 83 RBIs in 117 games at the Double-A level. He's since hit four homers in 16 games for the Sounds.
Chapman was joined by Barreto, the A's top prospect and No. 46 overall, just this week. Barreto already has three hits in nine at-bats for the Sounds, including a walk-off triple to cap Thursday's victory.
The shortstop was considered the key piece of the November 2014 Josh Donaldson trade for the A's, who are eyeing a formidable duo on the left side of the infield in Chapman and Barreto as soon as next season.
The A's received Montas in the trade that sent Josh Reddick and Rich Hill to the Dodgers last month. He has yet to pitch in the Oakland organization because of a rib injury, but he'll be able to make up for some of that lost time during his stint in the AFL, which celebrates Opening Day on Oct. 11 and concludes with its annual championship game Nov. 19.
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.