The Australian left-back is understood to have torn his anterior cruciate ligament after twisting his knee into the turf at training.
The 23-year-old, who has made 23 appearances for Hearts this season, is the third Jambos full-back to suffer a long-term injury this season.
On-loan Manchester United defender Demetri Mitchell sustained damage to his knee in Hearts’ 4-0 Scottish Cup win over Auchinleck Talbot on February 10, sidelining him for the remainder of the season, while Northern Ireland international Michael Smith tore his thigh muscle in the same game, and hasn’t played since - although the 30-year-old has commenced light running in training as he steps up his recovery.
Speaking on Thursday morning, Levein said: “We got a bit of bad news on Wednesday; Ben Garuccio has torn his cruciate in training, so he will be out for 10 months or so.
“His foot got caught in the turf and twisted, just a complete accident.”
Garuccio isn’t expected to kick a ball again in 2019 as a result of the injury, with recovery time for an ACL injury lasting anywhere from six to nine months after surgery.