The 18-year-old Chilean youth international is expected to complete a £3.5m move from Universidad de Chile to the Premier League giants later this month.
"If I go Manchester United it is to play," Henriquez told El Mercurio. "The team will be involved in several competitions, so I have the opportunity to get minutes on the pitch with the first team.
"I have spoken to Alex Ferguson and he said that I would be under consideration this season. That excites me.
"I know that I will have a very difficult task because there are players in the team like [Wayne] Rooney, [Robin] van Persie and Chicharito Hernandez, but I couldn't let this chance go by."
The Red Devils, who lost their season opener 1-0 at Everton earlier this evening, host Fulham on Saturday.