Perth Glory coach Ruben Zadkovich will seek answers from the referees department for the second week in a row after his side conceded a controversial penalty in a 2-2 draw with Central Coast.

Glory winger Salim Khelifi marked his shock early return from injury with a double to give the home side a 2-0 lead in Saturday night's A-League Men clash at Macedonia Park.

But penalties in the 74th and 81st minutes to Mariners striker Jason Cummings helped the Mariners secure a share of the spoils.

Glory could have no complaints about the second penalty - when Aaron McEneff clumsily stuck out his foot to bring down Christian Theoharous.

But Zadkovich was left fuming by the first penalty - a handball against Glory defender John Koutroumbis which was only awarded after VAR intervened.

Koutroumbis had leapt into the air and was about to land when an opponent volleyed the ball into his left hand.

The Glory defender wasn't even facing the ball at the time.

"Johnny Koutroumbis is not playing at the ball, his arm is by his side, it was not given a penalty at the time," Zadkovich said.

"So they (VAR) have obviously said clear and obvious error.

"I want to watch that back, because to me that looked like his arm was by his side, he's turned his back, he's not playing at the ball.

"Where is he supposed to put his arm? Has it gotten to the point where players actually have to remove their arms and hide them against their body?"

Zadkovich was also bemused by a series of other calls - or non calls - from referee Adam Kersey.

It came a week after Zadkovich was left frustrated by a fumbling fourth official who took too long to allow him to make a substitution.

Melbourne City went on to win that match 4-2, with the ladder leaders breaking the 2-2 deadlock while the fourth official was trying to process Zadkovich's requested substitution.

"It's another week where we'll go through a process during the week and ask the referees a lot of questions," Zadkovich said.

The draw means Glory are now four points adrift of sixth spot.

Central Coast remain in second, but could be leapfrogged by Adelaide on Sunday.

The Mariners had 69 per cent possession against Glory, and also finished the match with more shots (21-14) and corners (16-4).

"I thought we were by far the better team, the stats will tell you that," Mariners coach Nick Montgomery said.

"I'm really proud of the boys, but with 21 shots, 16 corners and 70 per cent possession, you should win the game."

Central Coast almost snatched the win, but Christian Theoharous's 82nd-minute thunderbolt from long range cannoned off the post.

Khelifi's starting role against the Mariners came as a huge surprise, given there were fears his season could have been over after he suffered a foot injury in Glory's 3-1 win over Melbourne Victory on January 21.

He opened the scoring against Central Coast with a free kick just outside the box in the 16th minute, and he doubled the lead in the 51st minute when he buried a penalty after a handball from Brian Kaltak.