Four times they bumped into one another, and although Barca scored eight times over the course of those encounters, Milan managed five goals and can look back, with careful filtering, on the results and contrive some encouragement.
Replicate the 2-2 draw at Camp Nou they achieved in the group phase and the 0-0 in San Siro in the home leg of the quarter-final, and that would be enough to get them through against the Spanish league leaders they face tomorrow.
But the fact is, this Milan have little use of reflection on what happened 18, 16, or even 11 months ago. So much has changed.
Here is a startling statistic: of the 21 players used by Milan against Barcelona over 360 minutes last season, guess how many were on the field when Milan completed their victory against Parma at the weekend?
The answer: two.
That shows the huge upheaval at Milan over the last two transfer windows, a rapid, wholesale transformation that ought to make any squad baulk at the prospect of taking on brilliant, streamlined Barca.
Yet the curious aspect of this reshaped Milan is their buoyancy. After four wins in five Serie A outings, they are undefeated in 2013. They now whisper the surnames of departed idols – Nesta, Seedorf, Gattuso, Van Bommel, Zambrotta – without shedding a nostalgic tear.
They utter the words Aquilani, Emanuelson, Mesbah and Maxi Lopez and nod in agreement that there were many on the staff who needed shedding.
They even watch highlights of the 2-2 ambush they achieved in Barcelona in September 2011 thanks to goals from Alexandre Pato and Thiago Silva without longing for those two departed Brazilians.
The only pity is Mario Balotelli – whose four goals in his first three matches as a rossonero have eased Zlatan Ibrahimovic and Antonio Cassano, both sold last summer, to an archive of the memory – is cup-tied for tomorrow.
The head coach Max Allegri concedes his surprise at the health of refurbished Milan.
"We are now able to aim for targets that seemed out of reach until recently," Allegri said.
Those include a top-three Serie A finish, now Milan have lurched up to third, joined on points with fourth-placed Lazio.
Whether the altered Milan can topple Barca, a machine built on the principle of continuity, is moot. But they feel bold about the challenge.
Follow us @SprtNationalUAE