With Ronaldo Mulitalo already out for most the coming season with a ruptured ACL, Katoa left the field in clear discomfort on Saturday.
The Tongan flyer went up the tunnel and is expected to undergo scans, after seemingly hurting himself while trying to break a tackle in the second half.
Playing close to their full-strength team, Cronulla completely outgunned a largely reserve-grade Raiders outfit at Gosford's Polytec Stadium.
Nicho Hynes and Braydon Trindall combined well and had a hand in three of the Sharks' first four tries, before they were pulled from the field after 45 minutes with Cronulla 22-0 up.
The pair linked up in the lead up to one Sam Stonestreet try, while Trindall dummied and offered up a smart cut-out ball in the lead up to Cronulla's first through Katoa.
Hynes' best moment came early in the second half, when he stepped his way through Canberra's defence and helped Hohepa Puru go in under the posts.
Nicho Hynes is in a running mood today! ��♂� pic.twitter.com/gRmEQXtLW9— NRL (@NRL) February 21, 2026
Puru and Briton Nikora both had some great moments, with the latter providing a great low-and-late offload for Jesse Ramien to score in the first half.
But the concern for the Sharks will be Katoa, who was one of the last regular first-graders still on the field when he was hurt midway through the second half.
Stonestreet is already expected to spend most of the season starting on the left wing, after Mulitalo ruptured his ACL playing for New Zealand last October.
If Katoa does miss the Sharks' season opener against Gold Coast in a fortnight, Mawene Hiroti would likely be Cronulla's next in line on the right wing.
Canberra also had a injury concern, with Matt Nicholson going up the tunnel early feeling for his left shoulder and failing to return to the field.
Canberra coach Ricky Stuart has opted against playing the majority of his first-grade players in both of the club's trials, with new halves pairing Ethan Strange and Ethan Sanders both kept on ice.