Pettis sustained an MCL injury Sunday against the Bears and is not expected to need surgery, Matt Maiocco of NBC Sports Bay Area reports.
It seems unlikely Pettis will play in the 49ers' meaningless Week 17 contest, but it's at least positive news that the rookie is not expected to need surgery. Kendrick Bourne figures to benefit the most in the event Pettis is indeed ruled out next week.