Washington Nationals prospect Tres Barrera has received an 80-game suspension after testing positive for Dehydrochlormethyltestosterone (DHCMT), a performance-enhancing substance, Major League Baseball announced on Saturday.

The 25-year-old catcher is on the Nationals’ 60-man player pool and is the team’s No. 19 prospect, according to MLB Pipeline.

Barrera filed an appeal for and lost, according to Bob Nightengale of USA Today.

“From the intial failed drug test to losing the appeal, this as all come as a complete surprise, as I have never, and will never knowingly use a banned substance,” Barrera said in a statement.