Tomori's injury was enough to make Milan collapse, melting like snow in the sun.
His departure turned the evening against Milan. In the summer, the club had considered him an 'outcast'. Milan reintegrated him only after the transfer window closed, then turned to him weeks later out of necessity.
Needing him so soon is another sign that Amorim has a desperately thin squad at his disposal.
The club bears serious blame for this. With the league, the Europa League and the Coppa Italia to play, alongside ever more international commitments and a growing risk of injuries, they should have assembled a bigger squad with more quality.
Amorim must shoulder his share of the blame. His stubbornness over Estupinan remains impossible to understand, as do certain substitutions yesterday. Hutchinson was one of the best players on the pitch, even out of possession. His pressing won the ball back several times, and on one occasion he supplied Cisse for the goal. Taking him off was a mistake.
By the final whistle, Milan's line-up was total chaos.