The man they call "The Hammer" adds to a growing casualty ward in Townsville, with Valentine Holmes picking up an injury in Origin 3 which will see him miss at least another two weeks.
Tabuai-Fidow filled in for Holmes at fullback during last week's tough home loss to the Sydney Roosters.
An official Cowboys statement said that following the appendectomy, Tabuai-Fidow will spend at least one night in hospital and will then be sidelined for six weeks.
However, NRL Physio on Twitter hinted that the recovery could be shorter.
The Cowboys expect Hamiso Tabuai-Fidow to miss 6 weeks after undergoing an emergency appendectomy. Recovery from medical procedures like this can vary, most are in the 3-5 week range. Adam Reynolds returned just 2 weeks after having his appendix removed in 2017
— NRL PHYSIO (@nrlphysio) July 21, 2021
With only seven weeks of the regular season remaining, it may be season done for Tabuai-Fidow, with the Cowboys looking more and more unlikely to make the finals with each passing week.
North Queensland currently sit in 13th place, and while they are only two points out of the top eight, their form is woeful, and the for and against record even worse in what is a logjam through the middle of the table.
The Cowboys have won just one game away from home all season, and with two of their three home games remaining against sides in the top six, the men from Townsville are facing a tough uphill battle to play finals footy.
Tabuai-Fidow has been one of their bright spots in 2021 though, with the winger making his State of Origin debut during Game 3 for Queensland and impressing on the wing with a try.
His performance backing up and replacing Holmes on the weekend was also superb, coming away with a try and 271 running metres.
All Run Metres
The Cowboys may now elect to call on young gun utility Daejarn Asi to play at the back until Holmes is able to return. The 20-year-old, with natural ability and speed, burst onto the scene last season, but has made just one appearance this season during the pre-Origin week against the Rabbitohs when both Holmes and Tabuai-Fidow were missing.
Javid Bowen will also be missing due to an ACL injury for the Cowboys, with Kane Bradley coming into the side. While Asi was named amongst the reserves this week, it was also thought Ben Hampton wasn't far away from a return, possibly giving the Cowboys another option in their depleted backline during the coming weeks.