GIANTS Captain Stephen Coniglio has suffered a head knock during an intra-club game, marking the second week in a row of friendly fire.
Coniglio is in good spirits, having walked off the ground after his collision with Daniel Lloyd on Friday morning at the GIANTS' base in Sydney Olympic Park.
If the midfielder is diagnosed with concussion he will be on reduced duties at training during the next 12 days as per the league's new guidelines.
The GIANTS' first and only pre-season fixture is against Brisbane in Canberra on March 7, however they are likely to organise at least one scratch match against Sydney in coming weeks.
"A bit of friendly fire. Both of them hit heads," coach Leon Cameron told AAP.
"Right now, he's fine. There's no concern.
"If it is concussion then he can't compete for 12 days ... he'd be able to participate in training with a red hat on, do some decision-making drills, but no contact."
Coniglio's scare comes a week after Lachie Whitfield suffered a bruised liver during match simulation.
Scans of Whitfield's collarbone, which required surgery in 2019, delivered the versatile star some good news but he knew something was still painfully amiss the following day.
"He copped a beauty, he was being too brave," Cameron said.
Whitfield's return will be determined by how quickly the organ heals, with the hard-running 26-year-old already ruled out of the GIANTS' tune-up against the Lions in three weeks.
Cameron hopes Whitfield, who last year topped the club's best and fairest voting alongside Nick Haynes, will be part of the Giants' season-opening clash with St Kilda on March 21.
"We don't know when he comes back, it'll be when the doctor says he can resume contact," Cameron said.
"It could be four weeks ... he may play if we have a little hit-out (before round one). Or we might bring him straight in for the St Kilda game.
"His fitness won't be a concern. Because he'll resume his running, weights and all that will be fine.
"It's unknown a little bit, but Lachie is the only concern in our mind. We've had a really good pre-season, out of 44 on our list we've probably averaged 41 (taking part every week)."
Key defenders Phil Davis, whose 2020 campaign ended prematurely because of knee surgery, and Lachie Keeffe are both expected to return to full training next week.