Central Coast Mariners assistant coach Matt Simon has denied his club has a discipline issue after winger Beni Nkololo was sent off in their 2-0 A-League Men loss to Western Sydney.

Nkololo was shown a straight red by referee Chris Beath after elbowing Wanderers defender Tomislav Mrcela in the 62nd minute at CommBank Stadium.

Mariners skipper Danny Vukovic had earlier been shown a yellow card for running to the other end of the field and remonstrating with Beath after Wanderers captain Marcelo was sent off for a lunging, two-footed tackle.

Simon – standing in for manager Nick Montgomery who was himself red-carded in last week’s draw with Wellington – was without defender Brian Kaltak and Brazilian forward Moresche on Saturday due to suspension.

“For us to get that red card like that was unacceptable,” Simon said.

“Beni’s thrown an elbow in his chest and the ref was looking straight at it.

“The coaching staff and the club will take care of that.< /p>

“Moresche was baited last week, and Brian was unlucky with a tackle.

“There’s no way there’s a discipline issue at the club (but Nkololo’s sending off) really hurt us.”

The loss means the Mariners have dropped five points in their last two games, with the Wanderers climbing above them into second spot thanks to back-to-back wins for just the second time this season.

Brandon Borrello had given the Wanderers the lead inside the opening half-an-hour with his fourth goal in his last three games.

The Mariners refused to give up and glimpsed a way back into the game when Marcelo was dismissed in the 52nd minute.

There was some deliberation after the Brazilian’s challenge on Storm Roux.

Beath showed the Wanderers man a straight red, then reviewed the decision on VAR before opting to uphold his own decision.

“(Marcelo) didn’t have to make that tackle because the ball was going out, but I was surprised it was a red,” Wanderers boss Marko Rudan said.

“We’ve worked on those situations and we were able to hold on, we got the second goal and that gave us some breathing space.”

Even with their skipper’s dismissal, the Wanderers were able to double their lead through Romain Amalfitano on the hour mark.

The Mariners were deflated, and Nkololo’s decision to lash out at Mrcela summed up a miserable afternoon.

Both Wanderers goals came as a result of some enterprising play by new Tunisian import Amor Layouni, the winger receiving a standing ovation near the end when Rudan gave him an early mark.

“We are yet to really unleash him, it’s going to take him a bit of time to get to that level,” Rudan said.

“He’s got that X-factor about him and he’s going to be a nightmare for defenders.”