Sydney FC coach Graham Arnold believes Football Federation Australia has every right to punish Perth Glory over their alleged salary cap abuses.

"The only thing I can say is that if they have breached the cap then whatever punishment they get is deserved," he said.

"That's what the salary cap is there for. If club's aren't going to live by it then we might as well get rid of it and let the owners spend whatever they want. If club's won't stick by it, then we have to abolish it, move on and every club can do what they like."

Perth Glory's hopes of a first A-League title may be dashed after Football Federation Australia issued the club a second show-cause notice for a serious breach of the salary cap.

It is understood the FFA will allege the Glory deliberately exceeded the A-League salary cap limit by approximately $150,000 by paying a player through a third party for the entire season. The fresh accusations could derail the club's hopes of playing in the finals series, with Perth facing the prospect of heavy fines and a possible points deduction should they be found guilty of systematically cheating the cap.

On the pitch, Arnold's focus is on Saturday's clash with Adelaide United. Ever since Adelaide appointed Josep Gombau as coach, the Reds have been widely lauded for their possession-based play, supposedly bringing a "Barcelona style" of football to the A-League.

According to Arnold, that's something of a ruse - and the Sky Blues coach says he has the statistics to prove it. While Arnold accepts Adelaide, who face Sydney in a huge match on Saturday night at Allianz Stadium, are attractive to watch, he says the idea the Reds are masters of the short-passing game is incorrect.

"I've analysed their last five games and they're tough. They obviously play a very long and direct game. Looking at the Opta stats yesterday, they've played over 1500 long balls during games this season at an average of 66 per game," Arnold said before Sydney training on Thursday. "That shows their intent. Their intent is to get the ball from back to front as early as possible and to get in behind you as quick as they can.

"I can only say what the stats say. They're a fantastic team, they've got some wonderful players but I look at the statistical side of things often and those stats don't lie."

Arnold said that Adelaide were also becoming increasingly physical - something that was especially apparent during the recent 2-2 draw with Melbourne Victory. "We've got to be ready for their [long balls] but we've also got to be ready for their aggressive defensive game," he said. "The stats also show they've given away the second highest number of fouls this year. We have to make sure that we're up for the fight as well."

The Sky Blues will be boosted by the return of Austrian marquee striker Marc Janko from international duty and midfielder Terry Antonis will be fit again after missing the past few weeks.

"Everyone is fine and the only problem is Shane Smeltz, who is out suspended, but Terry is back at last. We'll see how the next couple of days go for him," Arnold said. "Terry is in good nick. We've had to manage him carefully since he got back from the Asian Cup with his knee. He's done three days of good solid training but he'll be involved in some way on the weekend.

"Marc's fine, he came off at half-time [fo Austria], he's already texted me to say he's fit, he's excited, he's looking forward to the game and he's promised me a goal. We'll see how he recovers from the flight."

Arnold is hoping to give youth team striker George Blackwood, who has been away on Olyroos duty, another shot at some point before the end of the season.

"He's one of the brightest prospects in the country," he said. "We're trying to sign him for next year and he's a kid that can play as a nine, 10 or out wide. He's come through our system, he's trained every session with the first team and developed physically and you'll see a bit of him before the season is out."

Last week's 3-0 win over Wellington has given the side a huge lift, according to the coach, who believes it was the perfect tonic after the loss against Melbourne CIty.

"Whenever you beat the team on out of the league, it gives you belief straight away. There was always a good belief in the dressing room because we went nine unbeaten before Melbourne City," he said. "The main thing for me was how we would react after that loss, but we've got a lot of experience with players who've played on the big stage. They know what the business end is about and they can deal with pressure.

"We got a great reaction and the most pleasing thing was the team aspect. They carried out the game plan perfectly. We were defensively aggressive, perhaps the most I've been since I joined the club, and we didn't give the opposition any time of the ball. Against Adelaide, we've got to do the same."

This is the last match Sydney will play at Allianz before the finals and Arnold admits their form on home soil has been under par. "That's got to be the motivation. Our home form has not been special," he said.