You won't get any cash to help you recruit since you signed him. Also, if you are planning on applying for jobs in the next season or two, your reputation may take a hit. It is very unlikely, but possible, that another player might quit.
My suggestion is that balancing out classes is not worth rushing. If you want that, then be patient and handle it over the course of a few seasons. A senior heavy roster of high IQ players often outperforms their ratings. That said, if he's garbage and you think you have resources in hand to sign someone useful, then that may be worth the risk. I just wouldn't put any value on balancing classes in hurry.