Queensland forward Jeremiah Nanai has failed to train with the main group for the second time this week.
AAP has been told Nanai has "a niggle" to what appears to be his right calf and will be monitored throughout the camp to determine when he can return to full training.
The Maroons hope the second-rower can join the side for a full training session on Saturday and be available for game two of the State of Origin series in Melbourne on Wednesday night.
They had an opposed session against Queensland Cup side Easts Tigers at Sanctuary Cove on Thursday where Nanai was doing running on his own behind the goal posts.
He had a compression bandage on his right calf.
The 21-year-old has been an integral member of Queensland's squad since making his Origin debut in 2022.
Nanai missed game one of last year's series due to suspension but he returned in game two at Suncorp Stadium and had a blinder in a 32-6 win to help the side wrap up the series.
The Maroons' bench second-rowers Kurt Capewell and Felise Kaufusi alternated on the right edge against the Tigers in place of the absent Nanai.
While it appears unlikely Nanai will miss the MCG clash, both Capewell and Kaufusi are experienced Origin forwards and premiership winners with their former clubs Penrith and Melbourne respectively.
Capewell, now with the Warriors, is back in the Queensland side after last playing Origin in 2022.
Dolphins veteran Kaufusi was 18th man in the 38-10 win in game one but played after fullback Reece Walsh was ruled out of the match with concussion and NSW centre Joseph-Aukuso Suaalii sent off in the seventh minute.