LONDON, March 7 (Reuters) - Arsenal manager Mikel Arteta praised Manchester United's ( MANU ) character and legacy ahead of Sunday's clash while highlighting the boost his side got from their midweek 7-1 Champions League win at PSV Eindhoven as the key to maintaining momentum.

Arteta's second-placed side are 13 points adrift of Liverpool with a game in hand in the Premier League standings and six points ahead of Nottingham Forest in third.

Despite their 21-point lead over 14th-placed United, the Spaniard is not taking Ruben Amorim's side for granted.

"The history of United speaks for itself," Arteta said in the press conference on Friday.

"The players they have, the club they are - there's a legacy of overcoming difficult situations and they're always a dangerous opponent, especially when you least expect it.

"Watching their recent games, you can see the character in their squad. They are more than capable of putting in a strong performance and beating you on the day."

Arteta added that Arsenal would try to carry on the positive momentum from their stunning demolition of PSV on Tuesday in the first leg of their Champions League last-16 tie.

"What happened was we were super effective in the box and that's a massive strength, especially in the Champions League, and that's why we won the game with that margin," he said.

"The manner of the way we did it lifted everybody but that is in the past unfortunately. It is about what we do today, the preparation for tomorrow and trying to replicate a great performance again on Sunday.

"But (against PSV) things were coming at the right moment, at the right time, in the right way and that's very helpful, but every game is different."