Q: Can I submit a case report that has been previously published as a part of a case series by other providers?

Without knowing the details, it would be difficult to offer precise advice. However, based on only the information you have provided, the answer would probably be No. One reason would be the obvious one of lack of (or low) novelty, now that it has been published by other researchers. Another would be that you haven’t directly worked on this case (from what we understand). To be able to better decide, you may go through these related queries by previous researchers:

• Is it ethical to include an already reported case in a case series?
• Can I publish a case report about a medicine's side effect although two similar cases have been reported?
• Is it ethical to publish two different outcomes from the same case as two separate case reports?

If still not entirely sure, you may consider sending a presubmission inquiry to your target journal providing (only) a gist of your report.

Hope that helps. All the best for whatever you eventually decide.