Matri scored his first goals for Juve against his former club.
"It felt a bit weird seeing Matri score against Cagliari and for our opponents just a few days after he was here celebrating with us," confessed Donadoni.
"What can I say? He certainly didn't make Cagliari happy this evening."
Although Robert Acquafresca had been able to equalise, the Bianconeri emerged 3-1 winners.
"The team reacted well at the start of the second half, then we paid a heavy price for some naive moments.
"You feel the psychological blow when the third goal goes in and it is difficult to get back up that hill."