After not playing at all during the 2023 campaign, the 20-year-old is set for another long stint on the sidelines.
Richmond fear Gibcus has ruptured his anterior cruciate ligament in his right knee after landing awkwardly following a marking contest late in the second quarter of the Tigers' five-point defeat to Carlton at the MCG on Thursday night.
A distraught Gibcus left the field on a medical cart and was taken into Richmond's rooms.
If scans confirm the worst, it would follow Keidean Coleman (Brisbane Lions) and Sam Docherty (Carlton), who both suffered a dreaded ACL injury in last week's opening round.
"Obviously there'll be scans, but it's not looking great at the moment," Yze said of Gibcus. "We're touching all the wood we can that we get lucky with it. But if it is what we think it is, or could be, it would be obviously gut-wrenching.
"Not only the season he had last year, but just the type of player and the type of character he is. I feel for him so we'll wrap our arms around him."
Richmond fought bravely against the premiership-contending Blues, a big improvement on the Tigers' 39-point defeat to Gold Coast last week that started the Yze era at Tigerland.
Gibcus was not the only fitness issue to come out of the match, with experienced midfielder Dion Prestia suffering a hamstring injury.
Prestia has been cursed with soft-tissue injuries during his career, with Yze admitting they took a risk in playing him against the Blues.
Defender Tylar Young also failed to play out of the second-half after failing a concussion test, placing him in the 12-day protocols.
Yze said: "I feel for (Prestia). It was always a risk with a five-day break. You talk about pride and being proud of the performance, on the back of a five-day break, a hot day on the Gold Coast, to be able to sustain that performance the whole night.Â
"Even with Dylan Grimes, we were rapt he got through the game, but there was always the risk with playing some of our older players after five-day break. We'll live and learn."
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