Sir Alex Ferguson admitted Manchester United will face a tough test when they travel to St James's Park to take on Newcastle United in Sunday's English Premier League game.

"It's always a difficult place to go," Ferguson told reporters. "They'll be buoyed by their support. I think Alan Pardew has a really good team there. After the game against Tottenham we have to make sure we don't lose.

"We played some really good football at times (against Tottenham) and it was interesting to play Rooney, Chicharito and Robin van Persie together. It gives me some thoughts and options for certain games."

Newcastle have only lost once in their last eight games, incidentally against United in the League Cup, and Alan Pardew's side showed their current form with a comfortable 3-0 win over Bordeaux in the Europa League.

"I watched Newcastle last night and they played a few of their squad and left a few others out," Ferguson added. "But they still won convincingly. It was a good performance and a good result for them.

"Demba Ba and Papiss Cisse both have good scoring records. They rested Ba last night and played Shola Ameobi. I'm not sure what combination it will be on Sunday.

"Ba and Ameobi are both strong, while Cisse has scored some fantastic goals for them. The third goal last night was excellent."

Ferguson, meanwhile, has been impressed by the commitment shown by Robin Van Persie. "The refreshing thing for me is he's doing extra work in training because he's not had any preseason games," he said.

"It's quite remarkable considering he's got seven goals in (his last) seven games. I'm pleased with that and I think his fitness will improve even more.

"He's a good passer of the ball with good vision in his passing, too. The goal he made last week for (Shinji) Kagawa against Tottenham is evidence of his passing ability."

Van Persie scored 37 goals last season for Arsenal, and Ferguson is hoping for more of the same from the prolific Dutchman. "I would love that to happen," Ferguson added. "In my experience, and where we are at the moment, we need two strikers to get over 20 goals. If we get that, we definitely have a chance."