The Rossoneri have made a disappointing start to their Serie A campaign and are currently 10th in the league table with 13 points from 12 matches.
"We didn't think this sort of thing was impossible," he told Milan Channel. "But we have a great desire to get results.
"We're training well, but at the moment that is not enough. We need to take better care of the details. I think that's what will make the difference in matches.
"We can't look for excuses, we just have to work hard. As for my performances, I am happy – always try and do what the coach asks of me. I haven't scored enough goals, but I have a great relationship with the coach."
Matri joined Milan from Juventus in the summer.