Rule 3.7 - Lawyer as Witness(a) A lawyer shall not act as advocate at a trial in which the lawyer is likely to be a necessary witness unless: (1) the testimony relates to an uncontested issue;(2) the testimony relates to the nature and value of legal services rendered in the case; or(3) disqualification of the lawyer would work substantial hardship on the client.(b) A lawyer may act as advocate in a trial in which another lawyer in the lawyer's firm is likely to be called as a witness unless precluded from doing so by ER 1.7 or ER 1.9.Ariz. R. Prof'l. Cond. 3.7