The AFL released its rosters on Tuesday. Vitters has been sidelined with a broken hand after he was hit by a pitch in late July. He began the season at Class A Daytona and batted .291 with three homers and 13 RBIs in 28 games, then was promoted to Double-A Tennessee, where he batted .223 in 63 games.
"Vitters is healthy," Cubs player development director Oneri Fleita said. "He'll start taking ground balls this week. He starts hitting next week. The plan is to be ready for the instructional league [on Sept. 15] when we arrive and he'll play in the Arizona Fall League. He'll get the at-bats he missed and then go to our winter program in Arizona and get ready for Spring Training."
Jackson also began the season at Daytona and hit .316 in 67 games with six homers, 19 doubles and 38 RBIs. He was moved up to Tennessee on June 27 and was hitting .274 in 55 games with five homers, 11 doubles, five triples and 23 RBIs. Jackson was hitting .250 in August.
"It's the first time he's played 140 games," Fleita said of the outfielder. "He didn't get much time off. He's being challenged. As soon as [the Smokies] get into the playoffs, I'm sure his juices will get going."
The other Cubs players who will compete for the Mesa Solar Sox in the AFL include pitchers David Cales, Chris Carpenter, Jake Muyco and Kyle Smit and infielder Ryan Flaherty.
Cales has pitched solely in relief, appearing in 35 games at Tennessee and compiling a 2.51 ERA with 11 saves before he was promoted to Triple-A Iowa on July 8. A right-hander who was a 24th-round pick in 2008 and "throws from a different angle," according to Fleita, Cales has a 7.43 ERA in 20 games at Iowa.
Carpenter was 8-6 with a 3.16 ERA in 23 games at Tennessee, striking out 100 in 119 2/3 innings. He was moved up to Iowa on Aug. 24 and in two starts did not have a record. At Iowa, he has given up seven runs on 16 hits and six walks over nine innings.
Muyco, a converted catcher, appeared in 40 games at Tennessee (all in relief), where he posted a 3.67 ERA. He has pitched at Iowa this month, with a 4.91 ERA in 11 relief appearances.
Smit was acquired from the Dodgers along with Blake DeWitt for Ted Lilly and Ryan Theriot. In nine games in relief with the Cubs' Tennessee team, he's 4-1 with a 2.25 ERA.
Flaherty has played second, shortstop and third. He batted .288 in 101 games with Daytona, hitting nine homers, 33 doubles and three triples with 59 RBIs. In 23 games at Tennessee, he's batting .183 with one homer and two doubles.
"It's a good opportunity to go out and work on playing all the positions he can play," Fleita said of Flaherty.