can i fight for my job as a temp?

I have a pre existing injury long term I'm 30yrs ol in my wrist . the injury itself was sustained in my teens. 15-16yrs ago and never bothered me til the nature of my job aggregated it 3 yrs ago. My doctor at that time prescribed a wrist splint that I wear everyday only while lifting and working. I was with a different employer at the time and already had fulltime status so this new pain was covered under workmans comp in which I didn't take any time off to deal with. Just temporary lightened load. Yet I even waived that. And worked twice as hard 1 armed. Long story short that job ended and I found new employment under temp to hire status. During my temp probationary period I found this employment to be a great fit. With an amazing boss and crew. I don't want to be anywhere else. it was determined by my new boss that the company felt the same way. This is where it changes.. Less than 2 weeks to go with being a temp. I'm told from my sincere boss. That because of my injury I will never get hired. And that hits me like a ton of bricks. I know he's fighting for me to be there pleading my case for me. I was honest about why I wore it and yet it doesn't inhibit my production and I don't complain about it at work. Its just part of me unfortunately. Is there anything I can do cleanly without lawyers without a crap storm that would taint any reputation or hopes of this place being the place. I work hard everyday it doesn't effect my working hard.