Pinto initially injured his right shoulder Oct. 21 against San Jose after crashing into the corner boards after taking a hit from behind from Mario Ferraro on his first shift. He'd miss nine games before returning Nov. 13 against Pittsburgh.
However, Pinto re-injured his shoulder leaning in for a faceoff against the Penguins and hasn't played since.
"He has had surgery and he will be out for the foreseeable future," Senators head coach D.J. Smith said.
Pinto has tallied one assist in five games this year. In 17 career NHL games, he has one goal and eight points.
Smith did however leave the door slightly ajar for a possible late season return.
"He may come back for the last little bit but he could be done for the year," Smith said. "We're hopeful that he can come back maybe late March or April but we're certainly not going to hurry him. He won't be back anytime soon."
