No, it's not possible. The number needs to be visible on the screen in order for Truecaller to identify it.
How does Truecaller identify caller?
As many of you may have already noticed, Truecaller shows a caller ID alert saying 'incoming call by' and mentioning the name of the caller. The notification pops up around 3-4 seconds before the call actually connects and the phone starts ringing for the user to answer.25 Jan 2020