raised by the respondents of the running of the statute of limitations, § 473.083, there was no waiver of the exception for a failure to plead. Thus, the question is whether it was otherwise waived or abandoned. A party attempting to avoid the running of a statute of limitations by way of an avoidance has the burden to prove the avoidance or exception relied upon. Klippel v. Watkins, 667 S.W.2d 28, 30 (Mo.App.1984); Wardlow v. Denny, 579 S.W.2d 842, 843 (Mo.App.1979); Smile v. Lawson, 506 S.W.2d 400, 403 (Mo.1974). As such, where a question of fact exists for the jury to decide as to the existence of an avoidance, the party asserting it must request a jury instruction on the same; otherwise it will be deemed abandoned. See Young ex rel. Young v. Davis, 726 S.W.2d 836, 838 (Mo.App.1987) (<HOLDING>); Keller v. International Harvester Corp., 648
holding that theories of liability or defense pleaded and proved but not submitted are abandoned holding that issues raised but not supported by argument are deemed abandoned holding that issues not argued are abandoned holding that mitigation of damages is an affirmative defense that must be pleaded holding that a theory of recovery pleaded but not submitted to the jury by explicit agreement need not be considered on appeal