Hiring Agency Freelancers for Non UpWOrk jobs

[wptophat]

I am an UpWOrk Agency owner.

I have several UpWork freelancers in my agency. Not all of my work comes from Upwork. In addition to my freelancers submitting proposals, I want to hire them on occasion to complete work I pick up from other locations/platforms. For example, I have a client that signed up on my website. I would like to have one of my Upworkfreelancers to complete these jobs. How can I do that? Should I make an offer outside of Upwork and handle this as a completely separate contract?

I do not want to have to use an Upwork "client" account as that is just a PITA.

Please advise.