The imminent arrival of the fixture, which takes its nickname from one of the city of Milan's religious statues, has apparently cured bruises, sprains and pulled muscles, at least if you judge from events at the two clubs' practice grounds.
Take the three AC Milan players who variously withdrew from engagements with their national squads at the beginning of the week.
Kevin-Prince Boateng said no to Ghana's African Cup of Nations qualifier in Congo-Brazzaville and to a prestigious friendly at Wembley Stadium against England, citing the ankle problem that had troubled him lately.
Or Alexandre Pato, the striker who returned home to Lombardy from London, where he had been due to represent Brazil against Scotland, pointing to a swollen ankle joint.
Or Mark van Bommel, who withdrew from Holland's match against Hungary with a thigh complaint.
Surprise, surprise: by Thursday they were each declaring themselves back in shape, ready for tonight.
This is the match nobody wants to miss, set up with delicious suspense as a potential Serie A title-decider, and beyond that, 90 minutes on which a long-term cycle of mastery could turn.
Inter have been champions the past five years, are holders of the league, Champions League and Coppa Italia trophies, but they are trailing AC Milan by two points. If that becomes five points with seven matches to go, the momentum towards a first Milan Scudetto since 2004 looks powerful.
Form, though, is with Inter, who have dropped only two points from their last six matches. Milan have taken only one point from their last two league outings.
The impression of a pacesetter running out of steam is persuasive. Milan, although significantly rejuvenated with the summer additions to the squad of Boateng and Robinho, the promotion from the youth ranks of players like Alexander Merkel and the winter signing of Urby Emanuelson from Ajax, are still a side with a high average age, which in turn makes them sensitive to questions about whether they have the stamina for a tight battle over the last months of a long season.
They also go into the derby showing one very prominent symptom of frustration. Zlatan Ibrahimovic, the club's leading scorer this campaign, will watch from the grandstands at San Siro. He is suspended for an ill-tempered punch he plunged into the midriff of Marco Rossi of Bari during Milan's 1-1 draw with the struggling southerners.
Initially given a three-match suspension for the red-card offence, a Milan appeal reduced the ban by one match, so Ibrahimovic should return against Fiorentina next weekend.
The Swede's absence looks a key psychological advantage for Inter.
Not so long ago, Ibrahimovic was providing the thrust to lead Inter to scudettos, those of 2007, 2008 and 2009. He is as close to a championship-winning charm as exists in European football.
He won a Spanish league with Barcelona last season, and while he was with Juventus, they finished the 2005 and 2006 Serie A campaigns at the top of the table (though the titles would later be rescinded because of the calciopoli scandal).
Even without Ibrahimovic, there are plenty of crossovers. Andrea Pirlo, like Van Bommel and Boateng, is talking up his chances of being fit to take a place in the Milan midfield against his former club.
So is Clarence Seedorf, once of Inter. "The past is the past," Seedorf said to reporters who reminded him of the distant days when he wore his hair in long braids and sported the blue-and-black stripes of the city's other club. "Every derby has its own story."
And this one's novelty is Leonardo, who was in charge of Milan's first team for last season's two encounters with Inter.
His January appointment as Inter's coach has transformed the club from tired, fading treble-holders back into championship challengers, and it has changed Leonardo's outlook.
Leaving Milan after a season as coach and breaking a link that, as player and administrator, had endured for a dozen more years, had left him with some bitterness, and critical of his old club.
But ahead of his first Serie A meeting with Milan as an opponent, Leonardo spoke warmly.
"I live according to love not according to revenge," he said, "so when I look back on my years at Milan, I look back on the good bits."
Leonardo is similarly positive about his line-up. Although he may be without the defenders Lucio and Christian Chivu, the striker Diego Milito should be available for the first time in nearly two months. The Derby de la Madonnina has accelerated his recovery from injury, too.
Brescia v Bologna 8pm
AC Milan v Inter Milan 10.45pm
Napoli v Lazio 2.30pm
Catania v Palermo 5pm
Cesena v Fiorentina 5pm
Chievo v Sampdoria 5pm
Genoa v Cagliari 5pm
Lecce v Udinese 5pm
Parma v Bari 5pm
Roma v Juventus 10.45pm
Serie A table
Team P W D L GD P
AC Milan 30 18 8 4 29 62
Inter Milan 30 18 6 6 24 60
Napoli 30 18 5 7 19 59
Udinese 30 17 5 8 26 56
Lazio 30 16 6 8 11 54
Roma 30 14 8 8 6 50
Juventus 30 12 9 9 7 45
Palermo 30 13 4 13 -1 43
Fiorentina 30 10 11 9 4 41
Bologna 30 11 10 9 -4 40*
Cagliari 30 11 6 13 0 39
Genoa 30 10 9 11 -4 39
Chievo 30 8 11 11 -2 35
Parma 30 7 11 12 -12 32
Catania 30 8 8 14 -15 32
Sampdoria 30 7 10 13 -9 31
Cesena 30 7 8 15 -16 29
Lecce 30 7 7 16 -21 28
Brescia 30 6 8 16 -14 26
Bari 30 3 8 19 -28 17
*3 pts deducted for tax irregularities