"It's simple, Mario had that injury on international duty and his recent performances were not sharp, so I preferred to start with the pairing that played in the first leg," Allegri told Sky Sport Italia.
"He did some good things in the second half. Of course people expect a lot from him, he has to improve and get accustomed to playing every three days, which he has never really done before coming to Milan. That's tough both physically and psychologically.
"He did very well on a few occasions tonight, while in others he delayed the pass a bit too long. It is a particular shame for the third goal, as we had several chances to equalise this evening. The real regrets are that we didn't get the final pass right in a few different attacking situations."
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