Hudson-Odoi faces his former club in excellent form.
"We need to be aware and careful because today in football every game, no matter the competition, can be a difficult one," Maresca said.
"Nottingham Forest have a very good manager in Nuno and a very good squad. They are doing well, especially away from home – and beating Liverpool is never easy, especially away.
"They are doing well, it will be a difficult game and we will try to prepare our best.
"For sure, he (Hudson-Odoi) is a very big player for them. They have him and many more good players and we need to be aware of all of them.
"Not only about Callum but for sure he is one of the good players that they have and we will do our best to not concede chances against them, even though we will concede chances because that’s normal."