Mikolas (shoulder) will be shut down from throwing for seven-to-10 days after undergoing an MRI recently, Jeff Jones of the Belleville News-Democrat reports.
Manager Mike Shildt said "early returns are favorable", but the right-hander will still be prevented from throwing for at least a week while dealing with shoulder soreness. Mikolas hasn't officially been ruled out for Opening Day, but it's safe to assume he'll begin the season on the injured list since he hasn't thrown off a mound since Feb. 25 and will likely be unable to build up to a starter's workload.