Presumably the normal rules of disclosure apply, so there shouldn’t be any surprises? Or does CAS operate differently when it comes to legal process?
The text below is from the CAS rules and regulations, either party can introduce a new claim in their written submissions but once the other party has made a response then no further claims can be made without the consent of both parties.
R44.1 Written Submissions
The proceedings before the Panel comprise written submissions and, in principle, an oral hearing. Upon receipt of the file and if necessary, the President of the Panel shall issue directions in connection with the written submissions. As a general rule, there shall be one statement of claim, one response and, if the circumstances so require, one reply and one second response. The parties may, in the statement of claim and in the response, raise claims not contained in the request for arbitration and in the answer to the request. Thereafter, no party may raise any new claim without the consent of the other party.
Together with their written submissions, the parties shall produce all written evidence upon which they intend to rely. After the exchange of the written submissions, the parties shall not be authorized to produce further written evidence, except by mutual agreement, or if the Panel so permits, on the basis of exceptional circumstances.
In their written submissions, the parties shall list the name(s) of any witnesses, whom they intend to call, including a brief summary of their expected testimony, and the name(s) of any experts, stating their area of expertise, and shall state any other evidentiary measure which they request. Any witness statements shall be filed together with the parties’ submissions, unless the President of the Panel decides otherwise. If a counterclaim and/or jurisdictional objection is filed, the CAS Court Office shall fix a time limit for the Claimant to file an answer to the counterclaim and/or jurisdictional objection.