Manchester United manager Louis van Gaal has suggested that he is prepared to tinker with his team for this Sunday's derby against Manchester City at Old Trafford.

The Red Devils have been in a strong run of form, having secured five Premier League victories on the bounce and suffered just two defeats in 21 games.

Angel di Maria, Juan Mata and Ander Herrera are among the names who have been in and out of the team throughout the campaign, but Van Gaal is keeping his team selection close to his chest.

"'Never change a winning team' is an English expression, but I always have my eyes open," the Dutchman said in this afternoon's press conference. "It's also an obligation to the substitutes that you have to compare players.

"You have to see also the quality of your opponent and you make a decision with the staff I have. It's not always about never changing the team. I'm always confident because I believe in my team."

City have won the last four Manchester derbies, but Manuel Pellegrini's side have suffered defeats in their last three away matches in the league.