The 33-year-old striker suffered cruciate ligament damage in April last year and underwent major surgery.
His knee continued to cause him problems last season though and he has missed the last two league games after suffering discomfort.
"No other tears were found in the course of the surgery," Roma said in a statement, adding it was too early to say when he might play again.
Totti, who started the campaign in good form, had been linked with an Italy return for next year's World Cup having retired from international football after their 2006 triumph.
Mid-table Roma also announced on Monday that former Italy volleyball coach Gianpaolo Montali would work as a consultant for the club for the next two seasons.
He previously worked on the Juventus board and recently turned down an approach to become Napoli's sporting director.
