The Cubs have an off-day Thursday, and they hope Schwarber will be able to play Friday.
With Schwarber sidelined, outfielder Austin Jackson, acquired Monday from the Mariners, made his first start for Chicago and his first career start in right field.
• Hector Rondon said he does peek at the scoreboard radar guns to see how hard he is throwing. But it wasn't until Tuesday night that the Cubs reliever's fastball registered at 100 mph.
Rondon was facing the Reds' Eugenio Suarez with two outs in the ninth and a 5-4 lead.