Luckless Josh Gibcus has been reassured publicly that he is a "long-term" AFL player for Richmond after his latest injury setback was confirmed as a season-ender.

A hamstring injury sidelined Gibcus for all of last season and Thursday night was his second game back, but he fell awkwardly on the knee following a marking contest in the second term of the Tigers' narrow loss to Carlton at the MCG.

A distraught Gibcus left the field on a medical cart and was taken into Richmond's rooms.

The club confirmed the 20-year-old defender needs a knee reconstruction that will sideline him for the rest of the season, with scans confirming he ruptured his right anterior cruciate ligament (ACL).

New Richmond coach Adem Yze said post-match that Gibcus's latest career stall is "gut-wrenching", but the club is sticking by him.

"We are all incredibly disappointed for Josh. It is horrible luck after what he has already encountered on the injury front in his short career," Tigers football performance manager Tim Livingstone said in the club statement.

"Josh battled through last year with his head up and had put in a mountain of work to get himself back to full fitness for this season.