Former Manchester United assistant manager Carlos Queiroz admits he believed David Beckham was in decline when he arrived.

The Portuguese was brought in by Sir Alex Ferguson in 2002 and Beckham in his new docuseries admits they never saw eye-to-eye.

"Carlos Queiroz, who I knew nothing about, knew nothing of, didn't understand how he came in, but he did," Beckham recalled. "I never got on with him."

Queiroz says he and Ferguson could see Beckham's abilities waning, recalling his participating in one advertisement.

"Our observations and analysis, we start to feel David's performance was in a declining process," Queiroz explains. "I was mad with that situation. 'What's going on?'

"All of a sudden, one story comes out: the famous advertising of gladiators. A couple of players developed the upper body and if one player developed three, four or five kilos more of the upper body without the right coordination, it can affect their performance as a football player. It was clear it was not the same David.

"In 2003, guys like David, they're not only playing football, they are companies. It is a fight between things inside the pitch and outside the pitch. In that period, the business jumped inside the pitch."