GIANTS hooker Darren Turner could miss his side's big Super League IX opener against Castleford at the McAlpine on Sunday (3.00).
The 31-year-old vice-captain has been ordered to appear in front of RFL disciplinary chiefs tomorrow night after being accused of illegal use of the knees during the 28-0 pre-season defeat at Leeds Rhinos.
The news that Turner could be facing a suspension is a big blow to Sharp as he begins the final preparations for Sunday.
However, Sharp is equally as disappointed at the way in which Turner has been called, believing the Leeds club, now under the coaching control of former Giants chief Tony Smith, could have prompted the action.
"The club is mystified that Darren has been called up at such a late stage," said Sharp.
"The usual pattern of events is for the executive committee at the RFL to review match videos on Monday and immediately report to a club if they believe a player has a case to answer.
"But it wasn't until Thursday afternoon that we heard about Darren.
"As far as I am aware, the only way that can happen is if someone from Leeds reported him."
But Sharp has also admitted for the first time that he was concerned by his players' level of discipline during the Leeds game.
And he has demanded a big improvement against the Tigers this weekend .
"The players let the emotion of competing against their former coach get the better of them," he revealed.
"I found that disappointing and wholly unacceptable, and I've told my players that.
"It's clear that quite a few tough calls went against us, but the way we reacted was unacceptable.
"We can't afford that to happen against Castleford on Sunday. The stakes are far too high."