Weatherford said Wednesday he has a slight tear in the lateral meniscus and is leaning toward having surgery that would put him out a month.
"We're probably going to make the decision by the end of the week whether or not I'm going to be able to come back out, and it doesn't look like I'm going to be, so I'm probably going to have surgery as soon as possible," he said.
He injured the knee during last Saturday's scrimmage when linebacker Dekoda Watson attempted to strip the ball as Weatherford was running.
Weatherford, a senior, has started 33 games in his career.
Coach Bobby Bowden said he wasn't worried about Weatherford potentially missing the rest of spring practice because it allows sophomores Christian Ponder and D'Vontrey Richardson to get extra repetitions with the first- and second-team offenses.