In the Star Trek: Deep Space Nine episode "Apocalypse Rising," Worf, Sisko, Odo, and O'Brien infiltrate Klingon territory in an attempt to expose Gowron as a Changeling.
Memory Alpha does not mention Worf undergoing surgical alteration, and my recollection is that Worf was, at the time, a traitor to the Empire. A traitor to the Klingon Empire in the Klingon military headquarters would certainly draw attention!
Was the Federation worried that Worf would be identified by the other Klingons and therefore spoil the mission?
Or, was this possibility considered, but offset by other factors, like Worf's excellent knowledge of Klingon customs, or the large amount of bloodwine at the Order of the Bat'leth ceremony?