Tricare, VA, and HDHP coverage

I’m a military veteran rated at 80%, I get all of my care through the VA. I’m also a military spouse and am enrolled in Tricare prime though I’ve never used it. I recently started a new job that has a $0 monthly premium high deductible health plan with an HSA.

My question is would it make sense to disenroll from Tricare to be eligible for the HSA? Is disenrollment even an option? We’ve not been able to contact our base Tricare administrator.