Reds boss Gudjon Thordarson is furious with Isaiah Rankin after his behaviour during the appalling 6-1 defeat at Grimsby.
Rankin, who is on-loan at Grimsby taunted the Barnsley fans and players after scoring their fourth goal and should have been booked by the referee for incitement.
Gudjon said: "I thought he showed an attitude that for me as his manager is not acceptable and I'll deal with that when his loan spell is up at Grimsby".
"For my point of view it showed and tells you more about his attitude than anything else."
The heavy defeat was made worse by the news that recent new signing Garry Monk could miss the rest of the season through injury.
Monk went off after 19 minutes after colliding with Grimsby's Stuart Campbell.
"It looked like a serious injury and we might see Gary more or less out for the rest of the season," the boss said.
This means Monk may not play again until his contract expires.