The 18-year-old big man, who officially joined the Bombers under the father-son rule in November's NAB AFL Draft, went under the knife before appearing at the club's annual general meeting on Wednesday.
"He's had a minor 'scope to clean up a bit of cartilage that came loose from his patella," Essendon general manager of football operations Danny Corcoran told AFL.com.au.
"He just cooled down after one of the sessions and felt a bit sore, and he just reported it to the doctors.
"They had a look and found there was a piece of floating cartilage that they needed to take out."
Daniher will not be on a restricted training program for long.
"We're expecting him to be running on day one when we return (from the Christmas break)," Corcoran said.
"He's had a good six weeks before the break – he's really trained very, very well so far in the pre-season.
"He'll resume on January 7 when we're all back."
Another of Essendon's tall forwards, Scott Gumbleton, will step up his training load in January after shaking off a hamstring problem.
"It was a minor hammy. He was running yesterday," Corcoran said.
"He'll be good to go on January 7."
