Michael Lipman, Alex Crockett and Andrew Higgins say they are "extremely surprised and disappointed" to hear that they are to appear before a Rugby Football Union (RFU) disciplinary committee.
The trio, as well as Justin Harrison, have been charged with conduct prejudicial to the interests of the game, including taking prohibited substances and refusing to take a drugs test. A date for the hearing has yet to be decided.
Lipman, Crockett and Higgins all left Bath Rugby in protest at claims that they avoided taking a drugs test, while Harrison has since announced his retirement from the game.
A statement issued on behalf of Lipman, Crockett and Higgins, through solicitor Richard Mallett, read: "We are extremely surprised and disappointed both by the RFU's decision to convene a disciplinary panel and the terms of their statement.
"Any charges brought by the RFU will be vigorously contested. This is a matter that we take very seriously and will do everything possible in order to clear our names.
"For legal reasons we are unable to comment further at this stage."
Bath Rugby Chief Executive Bob Calleja said: "The Club treats matters relating to drugs very seriously and we are perfectly satisfied that we acted correctly in requiring the players to explain themselves at an internal disciplinary hearing.
"They chose not to do so and, so far as we are concerned, our internal process is at an end, the players no longer being employed by the Club.
"It would be inappropriate for the Club to make any further comment until the RFU disciplinary process is concluded."