"The plan is to be out there Thursday," Arrieta said after the workout.
"We're looking at [Thursday] right now, yes," Cubs manager Joe Maddon said. "We think that will be fine."
Cubs athletic trainer PJ Mainville wanted to make sure Arrieta felt OK on Wednesday, at which point the team announced Arrieta would be good to go. The veteran right-hander can possibly make three more starts in the regular season, including the finale at Wrigley Field on Oct. 1 against the Reds.
As to whether that would put Arrieta in line to start a potential National League Division Series opener, Maddon said he hasn't planned that far ahead. The Cubs began play on Wednesday with a 3 1/2-game lead over the Brewers in the NL Central.
Arrieta, who has missed two turns in the rotation, is 7-3 with a 2.01 ERA since the start of July and was holding opponents to a .191 batting average during that stretch.
"It's been good," Arrieta said. "The first extended [bullpen session], I was a little sore the next day, but I think that was kind of expected. It was the first heavy workload after the strain. The second day was a little sore and the day after that, it was back to normal. I feel that's a normal part of the progression.
"The good thing is the arm strength is there, it's remained there. I actually feel better for maybe having a little time off arm-strength-wise. We'll see how I feel [Wednesday] morning, but I anticipate to feel just fine and be ready to go Thursday."
Arrieta would most likely be limited to 75-80 pitches on Thursday and build from there.
"The idea is to be out there the last game against Cincinnati at full pitch count and to be ready for the playoffs," Arrieta said.