The Scot has been playing through the pain barrier with a hip issue but was substituted during his side's defeat to Benfica in the Champions League on Tuesday evening
The Hoops midfielder has been playing through the pain barrier despite being plagued by a hip complaint throughout the season.
However, Lennon has now conceded that it is time for the 27-year-old midfielder to go under the knife.
He told Sky Sports: “I think that’s run its course now, he’s not much energy now and I think he’s given us everything he could, more or less for every game.
“But it’s really tough to keep asking him to push himself when he’s in a lot of discomfort and distress, so we might have to shut him down and have the surgery.”
As well as losing his skipper for the final group game at home to Spartak Moscow Lennon must also do without Victor Wanyama, who will serve a suspension after picking up a booking in Portugal.
He added: “It’s a huge loss because he’s been magnificent for us and had a fine game tonight, so he’ll be a big miss.
“I feel for the player because the booking was ridiculous, I thought some of the decisions went against us tonight at times.”
The Northern Irishman went on to lament his side's defending at Estadio de Luz, citing nervousness as the cause for their porous back line.
He continued: “I’m disappointed in the two goals we conceded, particularly the first one were we’ve cleared it, but we haven’t picked up as we are coming out.
“There was a lack of composure, a nervousness about us on the ball, we’ve got to be bold, we had chances towards the end to get something out of the game.”