The JCC erred in designating Dr. Appley a “medical advisor” and relying upon his opinions to establish causation. Johns Eastern Co., Inc. v. Motto, 717 So.2d 91 (Fla. 1st DCA 1998); Washington v. Orange County School Board, 702 So.2d 1356 (Fla. 1st DCA 1997). Appellants timely objected to Dr. Appley’s deposition testimony. Clairson International v. Rose, 718 So.2d 210 (Fla. 1st DCA 1998). Therefore, we REVERSE and REMAND the JCC’s order for proceedings consistent with this opinion.