"He's playing well and moving all over the place," Maddon said of the Cubs' 2011 No. 1 Draft pick. "He's had good at-bats, more consistent at-bats, more under control. He's been doing well."
Baez struck out 130 times in 104 games last season at Iowa, and then fanned 95 times in 213 at-bats over 52 games with the Cubs after he was called up in early August.
Others expected to be added in the first wave on Sept. 1 include Quintin Berry and Emilio Bonifacio, who were both signed to Minor League contracts, and will be considered as options on the bench as pinch-runners.
Iowa's season ends Sept. 7, and the Cubs will add a few more players after that, Maddon said.
One option the Cubs are considering, Maddon said, is right-handed reliever Carl Edwards Jr., 23, who has a 3.03 ERA in 21 relief appearances at Iowa. Edwards was ranked No. 3 by MLB.com on the list of top 20 Cubs prospects.
"CJ is an interesting guy and I'm not exactly sure if and when, but I know [the front office] like him a lot, too, so I know that's a possibility," Maddon said.
• David Ross was not expected to rejoin the Cubs until the team returns home Monday. He is on family medical emergency leave, and was home in Atlanta.
"We told him to take his time, do the right thing," Maddon said. "What's going on with his family is more important."
Miguel Montero caught Jon Lester for the third time this season Saturday and was expected to catch Jake Arrieta on Sunday.
• Maddon was rooting for his home state Pennsylvania team in the Little League World Series. The Lewisberry, Pa., team beat Pearland, Texas, 3-2 with a walk-off RBI single Saturday.
"I'm really impressed with the poise of the kids," Maddon said. "You wish you never understood more and that you always processed the moment like they do. It was really fun to watch."
Is he trying to show the Cubs players how to keep that youthful innocence and energy?
"We are," Maddon said. "We're there."
• The Cubs will keep the bullpens along the foul lines next season rather than move them under the bleachers. The changes were part of the renovation plans at Wrigley Field, but the bullpens will stay where they are, because the team needs the batting cages currently under the bleachers.
"I like it," said Cubs lefty James Russell about being outside.
The pitchers like interacting with the supportive fans.
Said right-hander Justin Grimm: "It doesn't matter to me, honestly, as long as I have a place to warm up."