La Stella was batting .295 when he was optioned to make room for outfielder Chris Coghlan on the 25-man roster. Instead of reporting to Triple-A Iowa, La Stella went home. The Cubs placed him on the temporarily inactive list.
La Stella, who would be added Sept. 1 when rosters expand, will have to get some at-bats in the Minor Leagues, Maddon said. Iowa's season ends Sept. 5.
"There is enough time, but he's got to go do that," Maddon said. "There is enough time for him to do that and get ready for September."
• The Cubs have yet to announce who will start the first game of Tuesday's day-night doubleheader against the Brewers. The candidates include right-hander Trevor Cahill, who threw a bullpen session on Saturday at Wrigley Field, and lefty Mike Montgomery, who threw two innings against the Cardinals on Thursday.
Jason Hammel (12-5, 2.90 ERA) was expected to start the night game Tuesday for the Cubs.
• Reliever Pedro Strop, who had arthroscopic surgery on Friday for a torn meniscus in his left knee, was on crutches in the Cubs clubhouse on Saturday, and said he was feeling better almost immediately after the procedure.
Strop, who will be sidelined four to six weeks, was eager to start his rehab.
"I'll be back soon," he said.
• The Cubs began the day Saturday with a plus-200 run differential for the first time since the completion of the 1945 regular season, when they ended with a plus-203 differential (735 runs scored, 532 runs allowed).
• Brian Matusz, who signed a Minor League contract with the Cubs, then made one start on July 31 before he was designated for assignment, was back with the Cubs' Iowa team after clearing waivers. On Friday night, he gave up three runs over two innings in Iowa's 8-4 loss to Fresno.
Right-hander Josh Collmenter, 30, who signed a Minor League contract last week with the Cubs, was working out at the team's facility in Mesa, Ariz.