Best will remain on the standby list, as there could possibly be more injuries in the days and weeks ahead.
Lions manager Gerald Davies said: "Jerry Flannery tore ligaments in his left elbow in training on Wednesday and that unfortunately ruled him out of the tour.
"His place in the tour squad is taken by Edinburgh's 25-year-old hooker Ross Ford who played in all five of Scotland's 2009 RBS 6 Nations matches.
Commenting on the replacement, Lions head coach Ian McGeechan said: "Jerry has had a terrific season and he anchored the Irish scrum during Ireland's Six Nations Grand Slam season.
"It is disappointing that after selection for the Lions his season should end with a pre-tour injury.
"Injuries are a part of the game and while very distressing for the affected player we, as a squad, have to accept them as a fact of life. It is a part of the game we play.
"We are focused on moving forward, concentrating on the task at hand and the first match next week.
"Ross is a terrific player and he will naturally slot straight in as hooker. I look forward to welcoming him into camp tonight," he added.
The replacement player for Leigh Halfpenny will be announced in due course.
Meanwhile, Jerry Flannery was reviewed by an orthopaedic specialist on Thursday, who confirmed that surgery would be required.
He has had this operation today and will begin his rehabilitation immediately.