Star Red Sox lefty Chris Sale is slated to undergo an MRI on his elbow, skipper Ron Roenicke tells reporters including Jason Mastrodonato of the Boston Herald (via Twitter). At this point, the outlook isn’t known.

Sale reported soreness in the joint after throwing. He had dealt with some arm woes late last year, but seemed to be at full arm health as camp opened. Sale was delayed by illness, but the expectation was that he’d be able to ramp up as normal — just on a slight delay.

The results of the MRI will be sent to famed surgeon Dr. James Andrews for analysis. That’s alarming, at first glance, given that Andrews is known for performing so many Tommy John surgeries. That said, it’s also an obvious and sensible decision, given that the orthopedist treated Sale last season and is therefore intimately familiar with his medical situation.

There’s no reason to rush to judgment. But the situation is obviously concerning for a Boston organization that is entering an interesting and uncertain season. Just days ago, Sale told MLB.com that his arm felt good. Now, there’s sufficient cause for imaging.

Sale’s importance to the Red Sox largely goes without saying. The long-time ace is not only a key component of the rotation, but will occupy a big chunk of the team’s spending for the next several years. The extension he signed this time last year guarantees $145MM in salary from 2020 through 2024.