The Giants' campaign has been derailed by setbacks and Saturday's derby at Spotless Stadium delivered more bad news.

The 20-point loss is likely to cost GWS a top-four spot at the end of the regular season but the ramifications could be more severe for Davis and Griffen.

Davis was accidentally hurt by teammate Rory Lobb in a second-quarter marking contest while Griffen tweaked his hamstring in the third term.

Former Western Bulldogs captain Griffen, who has endured a frustrating run of injuries since joining the Giants in 2014, had only returned from a hamstring injury the previous week.

"That's a raw topic now because he's been such a great player for so long," GWS coach Leon Cameron said, when asked if Griffen could conceivably return in finals.

"You'd be disappointed, sitting there and thinking is it all coming to an end.

"I don't know how bad it is ... they said it was pretty minor.

"I'd punt on Ryan Griffen any day of the week in a final. He's a big-game player ... he just has to get his body right."

Already reeling from the loss of defensive general Heath Shaw to a season-ending knee injury, GWS's back six suffered a big blow when Davis limped into the rooms.

Davis returned to the fray after halftime but was no longer on match-winner Lance Franklin, instead hobbling around the forward line.

"Phil was sore in the lower part of his leg, his hip and his ribs. It was brave just going out there," Cameron said.

"He shouldn't have played after halftime but he's got a big heart."

It's the third week in a row the Giants haven't finished with a full bench.

Brett Deledio, Toby Greene, Dawson Simpson and Sam Taylor all went down during a big win over Carlton while Shaw, Josh Kelly and Sam Reid were all hurt in a gutsy victory over Adelaide.

"We still started with 22," Cameron said.

"Our players are really disappointed.

"You can't dwell on it or blame injuries, you're not going to get anywhere if you do that."

Australian Associated Press