Wada had to come out of his last start Monday because of soreness in his left shoulder, and if he can't go, the Cubs may use one of their relievers or promote a starter from Triple-A Iowa.
"We're not signing anybody new," Maddon said Thursday. "We're not having a tryout camp. There's so many different things and balls in the air right now, we're undecided."
• Maddon was critical of the replay format, saying Major League Baseball should consider an independent arbitrator of some kind rather than other umpires reviewing the video in New York. Maddon did not talk to anyone in MLB early Thursday regarding his comments.
"I often times say stupid things, so I'll just shut up," Maddon said.
• Jorge Soler was able to run on the field Thursday and is close to beginning a rehab assignment. The outfielder has been sidelined since June 3 with a left ankle sprain.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings. You can follow her on Twitter @CarrieMuskat and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.