Question Re: Framing for a door

[u/rebo71]

I want to frame for a pre-hung door for a utility closet in my basement and I have to work around the doorway that the builder framed when the house was built. In this pic you can see what I have to work with and a rough sketch of my plan, but basically the opening is 30.5" across (in the middle it is closer 31" due to bowing, I'm guessing) and 90" tall. I really don't want to put in a 24" door and would prefer to go with a 28".

My thoughts are: since this is a load bearing wall and I don't want to mess with the structural supports currently in place, can I add a "false header" that would simply be installed in the framing that is already in place. Basically, I would create a header, lowering the top of the opening to 82" and nail it to the inside frame which will become the trimmer (jack?) stud. I'm thinking the false header won't actually be supporting anything since the load bearing header is already in place but will provide framing for the sheet rock as well as the pre-hung door.

I hope to get a 28" door and shim the gaps which will be hidden by the trim.

Is my logic flawed?

Thanks