The Jamaican sprint king is an avid Red Devils supporter and follows the club's fortunes very closely, and when asked about his team's start to the 2014/15 campaign he pulled no punches with his verdict.

"We need a better defence," Bolt was quoted by the Independent telling reporters in Brazil. "I think that the problems are defence - we need to work on that.

"We don't have a good defence yet so I think a few more games we'll be better than we were. Our offence should be ok.

"It's a bad start to the season but that's how it is sometimes."

Opening day defeat

Manchester United's surprise 2-1 defeat against Swansea City at Old Trafford on Saturday will not have gone down well with supporters hoping for a fresh start following a disastrous season under the former stewardship of David Moyes last term.

Van Gaal looked to have made a positive impression on the Manchester United players following his arrival after the World Cup this summer, with the first-team squad maintaining a 100 per cent win record throughout pre-season.

However, that early optimism was dispelled after a poor showing against the Swans on the opening day, with emphasis once again placed on the need for the Red Devils to recruit more players before the close of the transfer window.

Incoming players?

A £15 million move for Sporting Lisbon defender Marcos Rojo looks to be on the verge of completion, with the Dutch coach seemingly taking Bolt's advice by addressing an apparent weakness at the back.

With £27 million summer signing Luke Shaw ruled out of action for the opening month of the season, Manchester United have been left short on left wing-back options and were forced to deploy Ashley Young in that unfamiliar position on Saturday.

Further defensive injuries saw Red Devils academy graduate Tyler Blackett handed his Premier League debut, but the 20-year-old struggled to settle into the game and was partly responsible for the conceding of Gylfi Sigurdsson's match winner.

Van Gaal abandoned his favoured 3-5-2 formation at half-time in an attempt to reinvigorate his side, but was unable to prevent his first game as a manager in England's top-flight ending in defeat.

It remains to be seen what other business Manchester United will do before the deadline, but with less than two weeks remaining it looks increasingly imperative that reinforcements are added if the Red Devils are to have any chance of heading back towards the top of the table.