Harbaugh said Patton will not be placed on injured reserve.
It's a tough blow for a wide receiver group already trying to make due without Michael Crabtree. Patton has seen limited playing time this season, but he was designated as the team's No. 2 receiver Thursday. His loss further depletes a position of weakness for San Francisco.
Keeping Patton on the 53-man roster indicates the Niners expect him back before the end of the regular season. The team already used their short-term injured reserve spot on rookie linebacker Nick Moody, recovering from a broken hand.
We'll see if Patton's injury spurs the Niners to explore the trade market. Right now, Harbaugh has Anquan Boldin and a whole lot of nothing.