Madden, playing five-eighth, left the field in the 61st minute of Saturday night's 34-10 win over Wests Tigers in Campbelltown.
He will have scans on Monday to asses the scale of any damage.
Centre Cobbo (shoulder) and Brisbane's regular No.6 Mam (finger) missed the Tigers clash.
The pair will train on Tuesday when their injuries will be assessed ahead of Friday night's showdown with the Roosters at Suncorp Stadium.
Captain Adam Reynolds and fullback Reece Walsh came off late against the Tigers with severe cramps, but the Broncos told AAP the pair pulled up well on Sunday morning.
The club are hopeful Madden's injury is minor.
Madden (l) is a doubt for Brisbane's Sydney Roosters showdown, Broncos coach Kevin Walters (r) says. (Darren England/AAP PHOTOS)
The last time the Broncos played the Roosters - in Las Vegas for March's high-profile season opener - Mam was called a "monkey" by Tricolours prop Spencer Leniu, who was subsequently suspended for eight weeks for the racial slur.
The incident, reported by Mam to officials on the field and supported in writing by teammates after the match, sets up an explosive re-match.
Brisbane coach Kevin Walters said after Saturday's Tigers victory that Mam and Madden were in doubt for the Roosters clash.
"I wouldn't think (Mam would play) ... and Jock, possibly not," Walters said when asked about the the duo's expected availability.
"We'll come up with something. I'm not sure. Jock is pretty sore and it's a shorter turnaround, but we're not going to put Ezra at risk this early in the season.
"We could play anyone there and they will get the job done for us."
If both are unavailable, Walters could slot the versatile Tristan Sailor into the No.6 role or shift Billy Walters - who has featured in the halves at NRL level previously - from No.9.
