Collingwood have been issued a "please explain" by the AFL after stars Jordan De Goey and Jeremy Howe were spotted with their phones midway through Friday night's loss to West Coast.
The injured Magpies pair left the ground and headed for treatment in the change rooms, with De Goey (concussion/broken nose) caught on TV camera picking up two phones and giving one to Howe (hamstring).
AFL rules bar players from using their phones during games due to integrity concerns, with only 10 people per club allowed to access them.
Players are expected to hand over their phones to a club compliance officer before the start of each match before they are placed in a secure box.
An AFL spokesman confirmed it has requested the club explain the star duo's actions.
Collingwood's season is on thin ice at 1-4, and they face a defining match against Essendon next week.
Coach Nathan Buckley is keen to continue the Darcy Moore experiment despite the side's defensive struggles in the 27-point loss at Perth Stadium.
Moore was swung into attack in a bid to fix the Magpies' goalscoring woes, and the All-Australian defender finished with three goals and eight marks from nine disposals.
"It's not a one-week thing. We need to get a little bit more evidence to see if that's something sustainable going forward," Buckley said.
"He looked dangerous at times. It's going to take him time to get a handle on it.
"The last time he played forward, the game was pretty different. So that's going to take time. But we needed to change things up, we're looking to get better."
Defender Mark Keane was dominated by Darling, and the Irishman could be in strife for a blatant and deliberate trip on Josh Kennedy that momentarily forced the star forward off with an ankle injury.
Buckley backed Keane to rebound from a tough night at the office.
Howe appears set for a lengthy stint on the sidelines after injuring his right hamstring in a marking contest.
The veteran defender immediately grabbed at the upper part of the hamstring, and he could barely bend his leg as he walked off.
Buckley is hopeful De Goey will miss just the one week with concussion.
Forward Brody Mihocek, who booted 2.5, will have his injured shoulder assessed.
Buckley cut a flat and frustrated figure after the loss, with the pressure ramping up on the out-of-contract coach to turn the season around.