The Old Trafford encounter was the England international's first start since Boxing Day, and just his third in all competitions in 2018, but Rashford told Sky Sports News that he does not have to be on the pitch to be learning under Jose Mourinho.
"Right now, I'm probably not learning the most on the pitch," the 20-year-old said. "In training is where I'm doing most of my learning. You have to take it into the game and [on Saturday] it worked. Personally, taking the confidence from this game into the next games is important.
"There's lots of things [that I'm learning]. It is just the all-round game is starting to become more clear. Things this manager wants are becoming more clear to me. The more you do, the easier the results come on the pitch.
"[Mourinho] doesn't have to [speak to me]. In football you are going to be up, you're going to be down. We are all in it together. Sometimes you are in the team, sometimes you are not in the team. But my experiences of the past - I understand that's part of the game. There are 11 players that start, it's just one of those things."
United face Sevilla in the second leg of their last-16 Champions League tie on Tuesday.