Evidence of Milan’s decline has been hard to miss in Italy of late. You can see it in the Serie A standings, where the Rossoneri began this weekend in eighth place, 17 points behind the league leaders, Juventus. You can hear it in the words of their manager, Pippo Inzaghi, who insisted after a 2–1 defeat to Sassuolo last weekend that it was time to abandon talk of a top-three finish.

Some fans even perceived it in the club’s latest transfer coup. After landing the Italy international Alessio Cerci on an 18-month loan from Atlético Madrid, Milan tweeted a picture of his new No22 shirt, hanging alongside Ricky Saponara’s No8 in the changing room at San Siro. As disillusioned followers were quick to point out, those squad numbers used to belong to Kaká and Gennaro Gattuso.

Speaking to Gazzetta dello Sport this week, the club captain, Riccardo Montolivo, candidly acknowledged that he and his team-mates lacked the quality of the players who had gone before. “None of us draw comparisons with the past,” he said. “They used to have sacred beasts at [the] Milanello [training ground], legends of European football. There is a clear difference between that Milan and this Milan.”

But misery loves company, and if there is one consolation it is that Milan’s city rivals have been going through a similarly difficult spell. Despite some encouraging performances, and impressive signings, to start 2015, Internazionale remained one spot behind Milan going into this weekend’s round of fixtures.

It is a long time since both clubs have simultaneously performed so poorly. This is the first season since 2001-02 in which neither has competed in the Champions League. You would need to go back another 60 years to find a campaign in which they each finished in lower positions than the ones they occupied on Saturday morning.

How did this happen? As recently as 2010-11, these were the best two teams in the country, Milan nudging Inter into second place as they ended their rivals’ run of five consecutive domestic titles. One year earlier, the Nerazzurri had become the first Italian team ever to win the treble.

For Internazionale, that was the beginning of the end of an era. The side that beat Bayern Munich in that 2010 Champions League final had an average age of close to 30 years old, and would bid farewell to their manager, José Mourinho, immediately afterwards. Over the years that followed, the likes of Javier Zanetti, Diego Milito and Wesley Sneijder would move on or melt away into retirement.

Having already poured more than €700m (£530m) of his own money into the club, the owner, Massimo Moratti, was no longer in a position to fund another overhaul. He sold a majority stake to an Indonesian businessman, Erick Thohir, in 2013. But the new owner continues to wrestle with the financial challenges at a club that posted losses of more than €100m on its most recent accounts.

Milan, too, have been fighting to get on to a more stable footing. The sales of their best two players – Zlatan Ibrahimovic and Thiago Silva – in the summer of 2012 were indicative of a growing acceptance that Financial Fair Play regulations could no longer be ignored.

With hindsight, it is remarkable that the Rossoneri – who also lost Gattuso, Alessandro Nesta and Clarence Seedorf that summer – remained competitive enough to grab third place the next year. That they did so is a testament to the work done by the club’s then manager Massimiliano Allegri, as well as an inspired half-season from Mario Balotelli.

The subsequent cuts at both Milan clubs have been drastic. Between them, Milan and Internazionale spent more than €120m on transfers before and during the 2008-09 season. By contrast, their combined outlay from the summer of 2014 through to this month is less than €30m so far. Milan made two-thirds of that amount back by selling Balotelli to Liverpool.

Wage bills have also been slashed. Gazzetta dello Sport’s annual survey of player salaries found that Internazionale were spending €70m on their first-team squad at the start of this season, while Milan were a little further ahead, on €94m. In 2011-12, those figures stood at €145m and €160m respectively.

And yet, those cuts must be kept in perspective. Even now, only Roma and Juventus spend more on player salaries in Serie A. In the longer term, the two Milan clubs will need to either upgrade or move away from San Siro to maximise commercial opportunities. But until then, there are still good reasons to believe they can do better than they have so far in this campaign.

Roberto Mancini’s return has restored enthusiasm at Internazionale, and made the club a more attractive proposition to players as well. The additions of Lukas Podolski and Xherdan Shaqiri have greatly boosted morale. A 1-1 draw at Juventus to start the new year hinted at growing potential.

Milan have made a less convincing start to 2015 but ended last year strongly by defeating Napoli and drawing away to Roma with 10 men. Cerci’s arrival gives them scope to grow further. He will never be the equal of Kaká but he did score 13 goals for Torino last year. A similar showing over the next four months would not fix all of Milan’s many problems. But it might at least help to focus supporters’ minds on the present, instead of a more glorious past.