He appeared to be a bad egg.

Now, Kalyn Ponga looms as a potential saviour for an injury-hit North Queensland ahead of Friday night’s NRL semi-final against Brisbane in Townsville.

Days after becoming embroiled in an alleged egg throwing incident, teenager Ponga is firming to feature in the grand final re-match after training on Thursday as cover for winger Antonio Winterstein (ribs).

In a move that left some shellshocked, Cowboys coach Paul Green admitted 18-year-old rookie Ponga and another “egg-gate” member Tautau Moga were on standby.

But it emerged late on Thursday that Ponga was all but locked in to become just the sixth player to make their first-grade debut in a final in 30 years after news that Winterstein was battling to recover.

It would cap a remarkable turnaround for either player.

The pair were among five Cowboys charged with two counts of wilful damage after allegedly being caught by police throwing eggs at passing cars last week in Townsville.

Moga and Jason Taumalolo were fined $2500 by the Cowboys while all five players agreed to pay for any damage to vehicles.

The players are due to appear next month in Townsville court.

However, Ponga or Moga might help a depleted North Queensland against their old enemy Brisbane.

“He (Ponga) trained with the boys along with Tautau Moga,” Green confirmed on Thursday.

“It’s a big game, a big occasion, but we will make that decision if we have to.

“At this stage, we are hoping Tone (Winterstein) will be right but there are a couple of options there.”

Ponga might not have played a NRL game yet but is already considered one of the code’s hottest properties.

He has already been named fullback in the NRL under 20s Team of the Year for 2016 and is expected to take out player of the season honours.

The Cowboys’ under 20s star has also become embroiled in an eligibility tug of war between Queensland and New Zealand after being dubbed the “next Johnathan Thurston”.

A question mark emerged over his allegiances after he opted not to play in this year’s Junior Test at Parramatta after both the Junior Kangaroos and Junior Kiwis revealed they wanted to pick him.

Not that Green wanted to put any more pressure on Ponga.

Asked if Ponga was poised to become a star of the future, Green said: “I don’t like putting tags on young players.

“I don’t think it does anyone any good.

“It just puts more pressure on kids.

“He is developing nicely but I am not going to put tags on him.”