A project manager on a high-risk project is concerned a schedule delay could push the go-live date. What should the project manager do next?

The project manager has identified a potential schedule delay, which is a risk. The appropriate next step in risk management is to record this risk in the risk register. This formalizes the risk, allowing for its analysis, planning of responses, and ongoing monitoring. The goal is to implement a planned response if the risk occurs, or to prevent it from occurring, thereby avoiding it becoming an actual issue. Submitting a change request for new resources is a potential risk response, but it's premature before formally documenting and analyzing the risk. Insisting on committed timelines ignores the identified risk and is not a proactive management approach. Asking the sponsor to initiate a separate project is an extreme and likely unnecessary measure without proper risk analysis and response planning.