Milan fell to a disappointing 2-0 defeat away to Torino on Sunday night, which leaves their hopes of a top four finish hanging by a thread.
The result has continued Milan's torrid run of form, as they have picked up just five points from their last seven games in Serie A, which is the third worst record in the league over this period.
The Milan boss was far from happy with the mentality of his players, who he says are making things harder for themselves. As quoted by Football Italia, Gattuso said: "We are having less fun than two months ago and that takes a toll. We’re not sharp, we think too much and that saps your enthusiasm.
"This is why I say that I can’t get in the heads of the players, as I want them to have the eye of the tiger, a constant grit and determination, but it’s not happening."
Gattuso, who spent the majority of his career at San Siro, felt his side's recent form was doing the club a disservice, adding: "I am tied to results, I am responsible. We are not only having embarrassing results for our team, we’re embarrassing an historic club."
The Rossoneri manager made the surprise decision to exclude Krzysztof Piatek from his starting lineup, despite being the club's most in-form striker.
He has come under scrutiny for the call, but when quizzed on this, Gattuso responded: "I picked [Patrick] Cutrone because we wanted to make forward passes quickly. Suso never came back inside, the team looked worried, we didn’t move well."
Milan's hopes of finishing in the top four now rest on the teams above them all dropping points. With three teams between them and fourth spot, Milan will probably need to take all twelve points from their final four games to stand any chance. However, as these all come against bottom half teams, the dream of a Champions League place may still live on.