CNN medical analyst Dr. Jonathan Reiner criticized Democrat John Fetterman’s campaign on Wednesday for not disclosing specifics about Fetterman’s “significant neurological injury.”

Dr. Reiner, a cardiologist and medical expert, told CNN host Jake Tapper than he admired Fetterman for getting on the debate stage despite suffering a “pretty significant neurologic injury.”

Unfortunately, Fetterman’s prognosis — a relevant question considering he could win election to the U.S. Senate — remains unknown because his campaign has not been transparent, Reiner added.

“Part of the problem is that the campaign was opaque. … they didn’t really disclose the degree of his illness. We don’t really know how sick he was,” Reiner explained. “In fact, his treating physicians were never made available — to the press or the public. So, we don’t really know how much Mr. Fetterman has actually recovered.”