If Real Madrid cannot claim to be perfect then neither can Celtic, according to Rangers boss Pedro Caixinha.

The new Ibrox manager will sample Old Firm action from the dugout for the first time when his side take on Brendan Rodgers' rampant Hoops in Sunday's William Hill Scottish Cup semi-final showdown.

The Light Blues support are praying their team can register their first derby triumph of the campaign at Hampden and halt Celtic's seemingly unstoppable charge towards a domestic clean sweep.

Read more: "Rangers manager Pedro Caixinha should hand Myles Beerman start against Celtic"

No Scottish side has so far been able to topple Rodgers' team this campaign, with the Parkhead men looking to chalk up their 47th game without defeat at the National Stadium.

And the exited Hoops faithful are confident their side can notch off one more result on their quest for an unblemished domestic season.

However, Caixinha reckons that even Zinedine Zidane's reigning Champions League winners Madrid have their flaws and so do Celtic.

But he does admit the challenge now for Gers is to prove they can take advantage of the chinks in Celtic's armour.

Read more: "Rangers manager Pedro Caixinha should hand Myles Beerman start against Celtic"

He said: "All teams have weaknesses - even the best teams in the world at this moment.

"It's difficult to pick out one from the Champions League semi-finals but if you say maybe it's between Real Madrid and Juventus, they all have weaknesses.

"The only question is can you identify them? Can you get your team to expose them and then exploit them?"

Celtic's chances will be boosted by the availability of their skipper Scott Brown despite his weekend red card against Ross County.

Brown is free to face Gers after the newly crowned Ladbrokes Premiership champions lodged an appeal against the dismissal, with the hearing scheduled to take place next Thursday.

He is unlikely to escape punishment, though, with the midfielder's lunge on Staggies striker Liam Boyce judged a sending-off offence by referee Don Robertson.

But Caixinha will not argue with Rodgers' decision to contest the case in order to make use of his captain.

"We would do the same," confessed the Portuguese coach. "If I had one player who was in my starting 11 or match-day 18 who I really counted on and had conditions to appeal, I'd do the same.

"So [Celtic] are taking the right decision."

Robertson did not get it all right in Dingwall, however, with his decision to reward County forward Alex Schalk's blatant dive with a penalty sparking a fresh round of debate on the standard of Scottish officiating.

The under-fire whistler will be on duty again on Sunday after being appointed as one of the additional assistant referees helping out Willie Collum.

That decision has been blasted by former Celtic frontman John Hartson, who believes the pressure being placed on Robertson could impact his decision-making skills.

However, Caixinha, who could have Clint Hill back from injury for Sunday's game, reckons the criticism has been too harsh.

He said: "I've had some very good chats with the league officials, so we have fantastic relations with all of them and fantastic relations with the fourth officials. So I have nothing to complain about.

"Even in the Kilmarnock game, when we analysed it after you could say we should have had three handballs. But sometimes that happens in a game. It's not easy to be a referee.

"When I was an under-15 player in Portugal, we went to a tournament in Lisbon and there was a game involving all the coaches. Somebody had to referee it so I offered myself and I found out it's not easy.

"Sometimes they take good decisions, other times they don't - like me, like the players and like the media when you need to write about one game. It's part of the deal and you need to respect it.

"It could be one decision that goes for me or goes for Brendan this weekend. The refs are human like us."