Arsenal manager Arsene Wenger is wary of the threat Celtic will pose at home as the sides prepare for their 'Battle of Britain' clash in Glasgow on Tuesday in a Champions League play-off.
A place in the illustrious group stages awaits the winner of the two-leg play-off and with it a massive guaranteed payday.
Glasgow giants Celtic negotiated a tricky qualifier against Dynamo Moscow in the previous round, coming back from a 1-0 defeat at Parkhead to win 2-0 in Russia - their first away win in Europe in 23 games.
Their recent defeat to Dynamo aside, Celtic have a formidable record at home in the Champions League with a long unbeaten record including wins over Manchester United and Juventus in previous seasons.
Wenger, who last season guided the Gunners to the semi-final stage of the competition, watched as his side demolished Everton 6-1 at Goodison Park in the opening fixture of the English Premier League on Saturday.
But despite this dominant display the Frenchman knows Tony Mowbray's side, who won 3-1 away to Aberdeen in the Scottish Premier League the same day, will be tricky opponents.
"It was a vital performance before the Celtic game," Wenger said of the Everton game.
"It will lift our confidence and that is good. But we're still on alert. We know every game is different and we still have to show we've matured as a team.
"I expect a high-paced game at Celtic Park. I watched some of their match with Aberdeen but for my taste, the game was too easy for them."
Arsenal defeated Celtic's Old Firm rivals Rangers 3-0 in the pre-season Emirates Cup competition.
However Wenger does not believe this points to an easy victory against the Hoops and says they wouldn't look out of place in the Premiership.
"Celtic have the dimension to play in the Premier League at the top. Celtic are on the international market as well, so it is not impossible for them to compete at this level.
"They and Rangers are the dominating force in Scotland and can take all the best players. Scotland has always produced good players."
Celtic manager Mowbray knows a lot about the Gunners from his time in charge of West Bromwich Albion in the Premiership last season.
He is a big admirer of Wenger's side but he insists the Hoops can pip them to a place in the group stages.
"I watched Arsenal defeat some of the biggest teams in Europe at a canter," Mowbray said.
"They are still a great side although maybe the cost of building Arsenal's new stadium has hindered Arsene Wenger's attempts to bring world-class players to the club.
"But he still produces great players and his team will always be there or thereabouts at the end of the season.
"We need to deny them space but can't be too negative. We must all be switched on and can't lose our concentration.
"They have good footballers who find the space to hurt you. But they can be vulnerable at the back and leave themselves exposed."
Winning the first leg could be vital as the history books show only one side has ever overcome a deficit to win in an all-British tie.
Wenger is hopeful that midfield duo of Theo Walcott and Abou Diaby will recover from back and groin injuries respectively to be fit for the match at Parkhead but Samir Nasri and Tomas Rosicky will miss out.
Celtic could be without central defender Glenn Loovens for the clash. The Dutchman only lasted 51 minutes of their win against Aberdeen as he limped off with a knee injury.
With Celtic captain Stephen McManus also sidelined it could leave Mowbray with a headache selection in defence.