Concussion blow for Aubusson, Roosters League News Out: Mitchell Aubusson. Sydney Roosters centre Mitchell Aubusson has been ruled out of Friday night's minor premiership showdown against South Sydney with concussion. Aubusson suffered the head knock in last Sunday's loss to Gold Coast at Allianz Stadium, but was given until Thursday afternoon to prove he would be fit to take on South Sydney. However, Roosters coach Trent Robinson confirmed on The Game Plan on Thursday night that Aubusson had been ruled out of the blockbuster clash at ANZ Stadium against their arch rivals. "He suffered a concussion last week and with a five-day turnaround he won't be right," he said. We thought we'd give him up to the last hour today to be right but he's not going to be right. There was speculation on Thursday that Sonny Bill Williams could be ruled out with a calf injury, but Fairfax Media understands he will play. Back-rower Aidan Guerra is the most likely to fill the vacant centre position left by Aubusson's concussion and force a reshuffle in the forwards and on the bench.