Sir Alex Ferguson was well known for wanting his players to have short and sensible hairstyles (David Beckham never played under him with a mohawk), so it was no surprise that he made Karel Poborsky trim his shaggy locks when he signed for Manchester United from Slavia Prague back in 1996.

In his new book, 'Leading', Ferguson reveals that he could not fathom why a player would have long hair.

"I never understood why players would want to have long hair. Anything, even a few extra locks of hair, just didn't seem sensible.

"I had my first issue with a player on this topic when Karel Poborsky came to Manchester United from Slavia Prague in 1996, looking as though as he was going to play for Led Zeppelin rather than United.

"I did manage to persuade him to trim his locks but even so, they were always too long for my tastes."

8 players that almost signed for Manchester United Show all 9 1 /9 8 players that almost signed for Manchester United 8 players that almost signed for Manchester United 8 players that Sir Alex Ferguson almost signed for Manchester United Sir Alex Ferguson's new book 'Leading' not only reveals the secrets behind the former Manchester United manager's success, but also lifts the lid on the transfers that nearly were. Here are eight players Ferguson almost managed to coax to Old Trafford with explanations from the man himself as to why they didn't quite work out. GETTY IMAGES 8 players that almost signed for Manchester United Ronaldo "We wanted to sign the Brazilian striker from Cruzeiro in 1994, but we could not get a work permit and he went to PSV Eindhoven." Getty Images 8 players that almost signed for Manchester United Petr Cech "I went to see him in 2003 for Rennes. We thought Petr was a bit young for the bruisers in the Premier League." 8 players that almost signed for Manchester United Didier Drogba "We went to check him out [at Marseille] but the club wanted £25million and Chelsea moved in for the kill before we had made up our minds." Getty Images 8 players that almost signed for Manchester United Thomas Muller "He was a ten-year-old when we heard about him. We had him watched and the following day he committed himself to Bayern Munich." GETTY IMAGES 8 players that almost signed for Manchester United Sergio Aguero "His agent was demanding a price we were not prepared to pay..." Getty Images 8 players that almost signed for Manchester United Raphael Varane "In 2011 I hurtled down to Lille. Zinedine Zidane got wind of this and somehow scooped him up for Real Madrid." Getty Images 8 players that almost signed for Manchester United Lucas Moura "We offered £35million but Paris Saint-Germain signed him for £45million." GETTY IMAGES 8 players that almost signed for Manchester United Mario Balotelli "In 2010 I briefly flirted with the idea of signing Mario Balotelli, the talented but controversial Italian striker. I did my homework on him, speaking to a few Italian contacts, but the feedback I got confirmed it was too big a risk." Getty

David Beckham revealed earlier this year that Ferguson once made him cut off his mohawk before the 2000 Charity Shield, in the Wembley Stadium toilets hours before kick-off.

David Beckham and his mohawk (GETTY IMAGES)

"I was in the dressing room with an hour to go before kick off when Sir Alex Ferguson saw it and made me shave it off," Beckham said in an interview which was broadcast on the Graham Norton Show on BBC 1.