Merrick: O'Donovan headbutt from the 'dark ages'

An irate Ernie Merrick says an ugly headbutt on Wellington Phoenix player Manny Muscat has sent football "back to the dark ages".

The Phoenix were pummelled 3-1 by the Central Coast Mariners on New Year’s Eve but it was the physical treatment dished out by Irish import Roy O’Donovan that stunned the Phoenix coach and  football watchers.

Referee Kris Griffiths-Jones handed the 30-year-old striker a yellow but the Match Review Panel are sure to take a closer look at the incident.

"I don't understand how someone can get away with that," Merrick told the ABC afterwards.

"That's going back to the dark ages. I've never seen that so blatantly happen.

"I'll bet there's some rule somewhere that says because a player got a yellow card for that they got off for it.

"That was the most disgusting thing I've seen in a while."

The headbutt, which flattened Muscat, came moments after the defender raised an arm to the head of O’Donovan. It is understood both players have been cited to appear before the MRP.

It was not the only incident to earn the ire of the Phoenix coach as Mariners kicked off their goal-scoring spree on 27 minutes with a dubious penalty.

Replays show that Muscat won the ball in the box but was somehow pinged for bringing down Josh Rose which allowed Fabio Ferreira to convert from the spot.

Merrick said it was a turning point.

"It was a clean tackle," Merrick told the ABC.

"Manny Muscat's got a reputation, but not since I've been at the club - he's changed completely."

Controversy aside the Mariners were clearly the better side on the night and were boosted by strong performances by Ferreira and Mitch Austin.

The result – only the Mariners second win of the season – leaves them rooted to the bottom of the table but puts Phoenix in danger of slipping out of the top six with the rest of the round still to play.