GREATER Western Sydney ruckman Rory Lobb has luckily escaped injury after a nasty collision with teammate Jake Stein at training on Wednesday.

The Giants' main session ahead of Saturday's clash with West Coast was halted immediately after Lobb crashed into Stein in a marking contest.

The players were on opposite sides during full-ground match simulation when Lobb flew for a mark and collected Stein, who was attacking the footy from the other side of the pack, in the head with his hip.

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Both players looked in serious trouble on the ground, with Stein seemingly knocked out by the impact.

They were immediately attended to by GWS medical staff while coach Leon Cameron gathered his squad in the middle of Spotless Stadium, but neither Lobb nor Stein could get up for several minutes.

The pair retreated to the change rooms before Lobb returned to the track and finished the session, while Stein was assessed for concussion.

Thankfully for the already injury-hit Giants, officials have cleared both players of any serious injury.

GWS is already missing stars Josh Kelly (groin), Toby Greene (foot), Tom Scully (ankle), Zac Williams (Achilles) and Brett Deledio (hamstring).

Lobb (knee) and Jeremy Cameron are likely return this week, but the star forward failed to train with the main group on Wednesday, so could still be in doubt.

GWS co-captain Callan Ward said the incident certainly sent a scare through the group, but it showed the type of intensity he's looking for from his teammates.

"I look at that and I think that’s great, Rory really wants his spot (back) and he's going really hard at the footy.

"At the same time, I'm thinking 'why are you getting injured in a training drill', but I think it's great for the club, and great for me that players really want a spot (in this team)."

Lobb should be right to face the Eagles after missing the past four games with bone bruising in his right knee.