Applied for a job last year now they want a phone screen, but I’m fresh on a new job. What should I say?

So I applied for a management job back in December when I was at my old job (I was there for 3 plus years). I’d forgotten about it and applied to others. I received an offer to the new job I’m at currently. I’m still in training to boot. Yesterday I got an email from the HR requesting a phone screen, should I tell them I’m at a new gig, pretend I’m at the old job, or not say anything? Anyone else been in this situation? How did it go?

Thanks!