Arsenal’s loss away to Manchester City should be in the back of the teams’ minds. It was a bad day at the office – though not as damaging as some may wish to portray – but it’s over and done with; it’s no longer an issue.

At least that’s the way title-challenging teams have to deal with setbacks. Take it on the chin, sleep it off and focus on the next match. Title-challenging teams should also not fear their foremost opponents in the race for silverware, especially if they’re topping the league table. But that’s part of the mood going into this Monday’s tie at home to Chelsea.

Why is there such a sense of trepidation? Chelsea, far from being awful this season, are a far cry from what they were four or five seasons ago. So what’s the problem? Yes, they’re a good, technically-gifted team who are capable of beating anyone on their day, but that’s not the case now.

People, both Arsenal fans and the “neutrals,” are quick to forget that Chelsea have lost away to Sunderland twice so far this season, as well as a host of more modest teams, while Arsenal have done exactly the opposite and taken maximum points from almost all of the “lesser” teams played this season.

It’s the Jose Mourinho factor. There’s a fear that the Portuguese, who Arsene Wenger is yet to beat in English football, will not so much become a banana skin ahead of a congested Christmas schedule for the Gunners, but one that will firmly displace them from lead place in the title race with a forceful and meaningful blow.

But why should the past always dictate the future? After all, trends in sports eventually have to come to an end. Forget Arsenal’s League Cup exit at the hands of Chelsea this season: not only is it a pointless trophy, at least for those competing in Europe, but Arsenal were caught in a position in the season where injuries dictated how far Wenger could exert his team for a competition quite firmly at the bottom of the pile.

Instead, Mourinho’s last league win over Arsenal came back in 2005. It was Mourinho’s Chelsea back then, a team fine-tuned to perfectly carry out the manager’s orders.

Since then, Arsenal have beaten Chelsea, the first of which came two months after Mourinho left the club in September 2007. And it would be wrong to label those Mourinho teams as “bogey” teams for Arsenal; no one was getting much from them during that two-year spell. Mourinho would walk with an eye-catching swagger into Old Trafford and confidently bat away Manchester United. Forget niceties and a respectful approach towards Alex Ferguson; it was all about climbing the Premier League ladder in the most convincing and destructive way.

But that’s in the past. Of course, Chelsea may come to the Emirates on Monday night and take all three points. Questions will be asked of Arsenal’s title credentials – though I’m not really sure why, a win is a win regardless of who the opposition is – and it will be another point on the board for Mourinho in what is now a far more cooled battle with Wenger.

Arguably, Wenger is on a level footing with Mourinho at this time. Maybe it won’t be shown in the outcome of Monday’s game, but it is shown in Arsenal’s ability to comprehensively beat the teams who Chelsea have struggled against. Moreover, the squad available to Wenger, even in the absence of the banned Jack Wilshere, is a match for the best Chelsea have to offer.

Arsenal as a club do have to overcome a mental barrier to get wins in these big games, but it’s not as deep-seeded as most would have you think.

Arsenal were outstanding when they hosted Chelsea in December 2010, winning 3-1 with the kind of performance that accurately exhibited the quality in Wenger’s side. The mental barrier that can come up during big games is one that is actually far more likely to crop up when playing the smaller teams in the league.

This time, Arsenal should have no fear. There’s already a really odd narrative flying around that Mourinho isn’t the same manager anymore, as if a flight from Madrid to London will someone sap an individual of their craft. But Arsenal can find comfort in the fact that this Chelsea team are ripe for the picking. They’re good, but they are yet to really hit top gear this season. They have issues at centre-forward, with unreliability being the prime. And to further Arsenal’s claim, Didier Drogba has long since departed.

Mourinho’s victories over Wenger in the past don’t speak of an inadequacy on the part of the Frenchman. The level playing field was mowed through with the arrival of Roman Abramovich, coinciding perfectly with Arsenal’s move into the new stadium.

As this is no longer of the Chelsea of old, a new chapter should be written. The landscape is considerably different now than it was almost 10 years ago.