This paper describes the addition of an extra piece of software, a rollback manager, to implement state saving and rollback management for optimistic federates in the High Level Architecture (HLA). This mechanism uses computational reflection techniques to create a rollback manager meta- object that extends the low-level time management services provided by HLA. The main propose of the rollback manager is to relieve the federate from the burden of handling problems related to the federate state saving management and recovery. Some experimental results are shown, to prove the feasibility of the proposed mechanism.