What will you do in this situation?

I am a Technical lead. Currently handling 4 different applications in the same project. All 4 applications are of team size of 10+ except one application.which is short of 3 resources and to balance that even I'm working as a developer since the workload is high. After requesting more resources, management has given me a guy who is from the support team and they want me to utilise him.

But in this application we need a senior developer with min 5+ years of experience as the project architecture is complex one and this guy who just learnt basic concepts, ( like a college student) but don't have the hands-on experience also

I don't want to give bad feedback for him but at the same time even I have to manage the load of other developers

I don't know what to do in this situation.