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If you believe Ronald de Boer, there is more resting on David Moyes' ability to rejuvenate Manchester United this summer than simply an improved season next year.

According to former Dutch international de Boer, in quotes reported by the Manchester Evening News, Robin van Persie could leave Old Trafford if he's not satisfied with Moyes' transfer business.

Van Persie wants to compete for trophies and everything this year looks out of sight. It’s very disappointing for a player of his quality. I don’t think he’s enjoying the football United are playing. He’s a team player but he likes to play beautiful football and that isn't the case at the moment. Man United need to refresh their squad. Some of their players have had fantastic careers but it’s time to move over and let some youngsters come through. Robin feels that, if this is happening, he will of course stay. But, if there’s no investment in new, young, great players from other clubs, then he will move.

It wasn't so long ago that van Persie was in the same position as some of the players United will target this summer. One of the best players in the world looking to move on.

As they did with van Persie, United will face competition from some of the biggest and richest clubs in Europe. Despite their struggles this season, United are still in a relatively small group of elite clubs.

Whoever is on their wish list is likely to be on a similar list at Real Madrid, Barcelona, Bayern Munich, Juventus, Paris Saint-Germain, Manchester City and Chelsea.

Luke Shaw—urged this week by former United youth coach Eric Harrison to move to Old Trafford—is perhaps a different case.

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Still only a teenager, it's unlikely that he could be tempted abroad should he decide to leave Southampton this summer. That might come later.

But for now Shaw's suitors are likely to come from the Premier League.

He's the type of player United made a habit of signing under Sir Alex Ferguson. Young and English, he's in a similar mould to Phil Jones and Chris Smalling.

In turn, United was the club that type of player chose to join.

They knew they would get a chance in the first team when the time was right. They knew they would get the opportunity to play in the Champions League, to win trophies and to push their international claims.

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After a difficult first season at Old Trafford, it will be up to Moyes to convince prospective arrivals that United can still offer all those things.

And it's vital for Shaw that, if he does decide to leave St. Mary's, he chooses well. Plenty of young players have moved to big clubs only to rot in the reserves.

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If Patrice Evra leaves when his contract expires at the end of the season, United could at least offer the 18-year-old regular football.

As de Boer says, there's a lot riding on Moyes' transfer dealings this summer. Not least determining United's place in the new pecking order when prospects like Shaw decide their next move.

If United can win the race for Shaw's signature, it would be a coup for Moyes, especially on the back of what is shaping up to be a miserable season.

A top English prospect showing that United, even in transition, are still the top English club.