Arrieta lasted just 1 2/3 innings for the second consecutive outing in Chicago's 15-10 loss to the Philadelphia Phillies on Tuesday.
"Something is going on with the way he's pitching," Cubs manager David Ross said Wednesday afternoon. "It's just best if we take care of that. Make sure that's not the cause of what's going on with him."
Arrieta blamed poor execution for his recent stretch. After compiling a 2.57 ERA through his first five starts of the season, the 35-year-old veteran has produced an 8.55 mark over his past 12, easily the highest in the league during that timeframe.
"I know where my stuff ranks in the game," Arrieta said after Tuesday's outing. "I watch a lot of baseball, and it's still there. It is. This is a tough stretch for us as a team and for me individually."
Ross indicated that instead of leaving it up to Arrieta to continue 'pushing through' the manager would make the decision easier for the player.
"It's my job to take that out of his hands and do what's best for him and us," Ross said.
The Cubs have lost 11 straight heading into Wednesday's matchup with the Phillies.
"I contributed to the continued stretch that we're on, and that doesn't sit well with me at all," Arrieta said. "There is still a lot left in the tank. No question about that. The stuff plays. The execution is not there. It hasn't been for a while but I've been in similar situations in my career. I've been in worse situations than this."
Also on the injury front, third baseman Kris Bryant exited Wednesday's game against the Phillies with right hamstring tightness and is day to day. He was replaced in the lineup by Patrick Wisdom in the top of the fourth.
Javier Baez, who was a last-minute scratch with a sprained right thumb Wednesday, also is day to day.