However the surgery the following month appears to have been a success and O'Brien is nearing a return to full-time training with Leinster.
And while Murphy is not about to make any promises, he does believe that the Irishman is closer than ever to making a return.
"For Seanie, there's no return date on him but he's doing really well," said Murphy.
"He isn't training fully, he's on modified training, but he's not a million miles away from being back in the team environment.
"It is possible that he'll play before the end of the season, but no decision has been made on that as yet.
"He's back to see a specialist this week and the progress that he's made has been really good. He's not a million miles away from being back with us training properly."