The 20-year-old has just returned from Brazil where he received treatment for a muscle injury.
Speaking to Italia 7 Gold at Milan's Malpensa airport, Pato said: "I feel good and I will certainly be there against Manchester United on February 16.
"I watched the derby on TV. We lost. But the season isn't over. There are still many games left."
Pato then tried to encourage his team-mates after last night's 1-0 defeat at home to Udinese knocked Milan out of the Coppa Italia.
"We made a lot of hard work with Udinese, especially in the build up play. We allowed Di Biasi's side to counter attack on numerous occasions.
"We had players on the pitch who were coming back after a long time out, others who usually play a little less than the regulars, but in spite of this our performance was below our potential.
"We shouldn't make a drama after two consecutive defeats. If we analyse the two games, it's clear they were both different, in different competitions.
"Now we have to recharge our batteries with calm, but I believe that by the end of the day we'll be feeling positive."