GWS forward Devon Smith will miss the next six weeks for the Giants after suffering a knee injury at training.
Smith tore his meniscus in the Giants' final session before their home match against Richmond on Saturday, and will now undergo surgery to repair his knee.
The 23-year-old will miss at least six weeks, but could be sidelined for up to 12 weeks.
"He had an unfortunate accident changing direction and tweaked his knee, and has torn his meniscus," coach Leon Cameron said.
"It's really disappointing because you don't expect to lose players the day before the match, but it is what it is.
"The positive side of it is that Matt de Boer comes into the 22 and gets the chance to wear the Giants jumper for the first time."
Smith now joins Stephen Coniglio, Nick Haynes, Jacob Hooper, Ryan Griffen, Brett Deledio, Matt Buntine and Adam Kennedy as long-term outs for the Giants.