Van Gaal faces many questions as Premeir League season looms

Manchester United's fourth place in last season's Premier League was regarded as a qualified success but more importantly the launch pad to return the club to former glory.

A few weeks later, however, with uncertainty over the future of goalkeeper David de Gea, Angel di Maria's expected sale to Paris St Germain rumbling on and worries about virtually every area of the pitch, United's legions of fans still need convincing that things are moving in the right direction.

Manager Louis van Gaal's first season in charge was greeted with a general thumbs up as the Dutchman returned the team to top four after their stunning fall from grace under David Moyes.

Improving on that will be an even bigger challenge.

Former United defender Rio Ferdinand, who won six Premier League titles under Alex Ferguson, says that Van Gaal faces a "massive season" and will have "no excuses" if United fail to challenge for a 21st league title.

"He's had last season and a whole pre-season to really drill his ideas and philosophy into these players," Ferdinand told reporters.

"He is under pressure to win the league, or at least to improve and finish in second place."

Chief among Van Gaal's concerns will be goalkeeper De Gea, who is wanted by Real Madrid. The Spaniard appeared distracted when United lost 2-0 to PSG in a friendly last week and the sooner his situation is cleared up the better.

Then there are concerns about the physical condition of new signing Bastian Schweinsteiger from Bayern Munich.

The German midfielder's pedigree is beyond question but the 14 million pounds ($21.85 million) United paid for the 31-year-old will only represent a sound investment if they have signed the powerhouse he was at his peak -- not the injury-plagued player whose influence was on the wane at Bayern.

Van Gaal showed faith in English defenders Chris Smalling and Phil Jones last season but neither were convincing.

Sergio Ramos has been mooted as a possible signing, but only as part of a deal that would take De Gea to Madrid.

With Robin van Persie gone, Van Gaal will hope Memphis Depay, who lit up the Dutch league with PSV Eindhoven, will form a potent strike partnership with talisman Wayne Rooney.

French midfielder Morgan Schneiderlin was also signed from Southampton. But there is a feeling of more questions than answers as United go into a crucial opening period which begins at home to Tottenham Hotspur on Saturday and continues with a vital Champions League qualifier the week after.

"Time will tell if (Van Gaal) has bought well," Ferdinand said. "Schweinsteiger has won all there is to win in the game, but the Premier League is a different beast, Depay hasn't played here -- they still have to prove themselves.