The Spanish international full back sustained the knock towards the tail end of last year, but it was originally thought that complete rest would clear up the problem.
However, the 27-year-old has not progressed as expected, and has now been sidelined for a month.
Celta club doctors carried out further tests on the injury earlier in the week, and it has now been decided that the left-sided full back will go under the surgeon's knife.
The operation is likely to keep Juanfran out of action for at least six weeks, thus ruling him out of Celta's UEFA Champions League tie with Arsenal in late February.
Meanwhile, Brazilian midfielder Vagner has controversially attacked some of his Celta team mates, and sections of the club's fans, claiming they were responsible for getting Miguel Angel Lotina the sack.
The South American feels some players did not show the on-field commitment to mirror their words of support for the deposed coach, and hit out at supporters for their short-term memories.
"I am not a creep, but I regret the fact that some players who defended Lotina most did not put it in for him in his most difficult moments and brought about his recent sacking," he declared.
"I expect nothing from the fans in the Balaidos because they only support us when we are winning.
"I can't understand the behaviour towards Lotina from the majority of them when he was the only manager in the club's history to have taken us into the (UEFA) Champions League."
