Where an expert has been specifically employed in preparation of litigation but is not to be called as a witness at trial, the facts known or opinions held are deemed to be work product and may be discovered only by a showing of exceptional circumstances, as mandated by Fla.R.Civ.P. 1.280. Rocca v. Rocca, 38 FLW D2378 (Fla. 3rd DCA 11-13-2013).