Young Sydney star Callum Mills will miss the rest of the season.
Mills broke his foot following an incident after training on Thursday.
He was throwing a gridiron ball with his teammates on the way back from a café in Moore Park when he tripped and fell, breaking his foot.
"It was a really unfortunate accident and unfortunately Callum has an operation on Monday and will be out for the rest of the year," Sydney coach John Longmire said.
"It's a bad break...it's something out of the blue and clearly very disappointing for us."
Mills is one of two changes for Sydney this week, with Gary Rohan also dropped.
Harry Marsh and debutant Ryley Stoddart have come into the side.
"Baz, you know I wouldn't say that!" Barry Hall had a classic response to a line from JB on Triple M's Rush Hour.