Contreras, 30, has been dealing with the issue since rolling the ankle while running the bases in the Field of Dreams game against the Reds last month. He has a career-high 128 OPS+ in 107 games this season, his last before becoming a free agent.
Miley, 35, has been on the injured list since mid-June because of left shoulder issues that have limited him to only four starts this season. He was claimed off waivers from Cincinnati last offseason after spending 2020 and ’21 with the Reds. He has a 2.84 ERA in 19 innings pitched this year.
The Cubs on Tuesday also activated outfielder Michael Hermosillo from the injured list and designated pitchers Luke Farrell and Nicholas Padilla for assignment.