Nani believes the Gunners pose a bigger threat to United than Chelsea in the race for the Premier League title.
“Arsenal are a bigger threat than Chelsea now,” he said. “Chelsea have lost a few games and drawn some and their confidence looks a bit low.
“But Arsenal have been winning and being top of the league gives you great confidence.
“Arsenal have been doing well. They are growing up in the way we are.”
After facing Arsenal, United will travel to Chelsea for their next Premier League game.
“Our momentum is growing,” he added. “Players like Wayne Rooney and Anderson are starting to play fantastically again.
“It is great because our next two games are going to be very important for us.
“If we win against Arsenal and Chelsea we will be in a very good position to win the league.”
“I like to play against Arsenal,” he said. “It is good playing against any big team but I have done well against them in the past.
“The way they play gives you a chance to show your quality.”