Greater Western Sydney's injury crisis has deepened with veteran Brett Deledio set to be sidelined for up to 10 weeks.

The 31-year-old suffered a fresh calf strain at training on Friday in his return from a four-week hamstring injury.  

Giants head of athletic performance David Joyce confirmed the news on Monday.  

"It's the other side to what he hurt and kept him out for large periods of last season, but it means we're going to have to take an extended break for Brett and rehab him again and get him back towards the back end of the year," Joyce said. 

"It's slightly different in that it involves the tendon. His past history of soleus strains is something we have to consider very carefully with this." 

"He's obviously a crucially important player for us and we want to make sure we play a really conservative card to start with and build his loads up gradually."

GWS have lost their past four matches and travel to Adelaide to take on the Crows this Sunday.