I know next to nothing about the structure of a knee and know even less about the impact of particular injuries to them... But a partial tear sounds a little bit less impactful than a full tear or tears to multiple ligaments with regard to impact on his long-term recovery and even on his career.
I'm willing to bet we will see Brian Hoyer start another game for the Cleveland Browns before it's all said and done.
EDIT:
Nevermind.
<blockquote class="twitter-tweet"><p>Chud said not partial but full tear for Hoyer - "It is a tear but there is no other ligament or cartilage damage which is a good thing"</p>— Daryl Ruiter (@RuiterWrongFAN) <a href="https://twitter.com/RuiterWrongFAN/statuses/386160514054643713">October 4, 2013</a></blockquote>
<script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>