Cubs general manager Jed Hoyer said the team had expected Baez to go through "more of a process."
"He's had more success than we expected," Hoyer said of the Cubs' 2011 first-round Draft pick. "He got over that initial Double-A hurdle quickly, and he's been on a hot streak. Good for him. It's been impressive that he adjusted as quick as he did."
The shortstop is finishing on a high note.
"Hopefully, he'll carry that forward into next year, the confidence he had in Double-A," Hoyer said. "I think when he made the jump from High A to Double-A, we felt giving him the challenge was the right thing to do, and he's responded."
Baez will not play in the Arizona Fall League, but prospects Jorge Soler and Albert Almora will. The official AFL rosters were expected to be released later this month, and Hoyer said the Cubs would have an impressive group.
The Cubs have yet to finalize who will be called up to the big league roster in September, but the team will most likely add players who are not currently on the 40-man roster but expected to be added this offseason.
The Cubs also hope to add Luis Valbuena (right oblique strain) and Ryan Sweeney (left rib fracture), who were both on the disabled list.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.