MELBOURNE defender Joel Smith will miss the rest of the season with a leg injury, but he has escaped a 12-month stint on the sidelines with scans revealing no damage to the anterior cruciate ligament in his knee.

The Demons were fearful the young defender may have ruptured his ACL after sustaining a serious injury while playing for the Casey Demons against Sandringham in the VFL on Saturday.

But Demons football manager Josh Mahoney said the injury was not as bad as first thought, with the 21-year-old to be sidelined for between eight to 10 weeks with a crack in his tibia bone.

"Joel Smith landed awkwardly after a marking contest on the weekend playing for Casey and left the ground on a stretcher," Mahoney told the club website.

"Scans today (Monday) have shown a crack in his tibia bone. A decision will be made this week regarding the need for surgery, nevertheless he will not play again this season.

"This injury generally takes approximately eight to 10 weeks to heal and Joel will be fully recovered at the beginning of pre-season."

Smith has played three senior matches for the Demons this season after being elevated off the rookie list to make his debut in round one against St Kilda.

However, he will not remember his first senior game fondly, with the defender suffering a dislocated shoulder just 15 minutes into the match.

Smith, who signed a new two-year deal after sustaining the shoulder injury, missed three months before making his return via the VFL.

The athletic defender returned to play against Carlton in round 16 but lost his place in the side after the Demons' loss to Adelaide in round 17.

Smith missed last week's VFL match after a mishap where he hurt his hip slightly at training, before suffering his latest setback at the weekend.

"Joel has had a frustrating year with injury, and as disappointed as we are with his season being over, there were initial fears of even more damage being done to the knee, which would have affected next year," Mahoney said.

Smith, the son of former high-flying Demon Shaun, was recruited to the club via the three-year non-registered player rule and was listed as a category B rookie.

Despite his latest setback, the Demons have high hopes that the 191cm defender will be an important part of their back six for years to come.