Former Manchester United boss Sir Alex Ferguson believes he knows how to stop Barcelona star Leo Messi.

The two teams meet next month in the Champions League quarterfinals.

Ferguson's United side came up against Messi's Barcelona in the Champions League final in 2009 and 2011, losing on both occasions, and following the two defeats he set up hatching a plan to stop Messi should he ever face him again.

"To beat Barcelona in that cycle you needed centre-backs who could be really positive," Ferguson wrote in his 2013 autobiography.

"Rio and Vidic were at an age where their preference was to defend the space. Nothing wrong with that. Quite correct. But, against Barcelona, it's a limited approach.

"You need centre-backs who are prepared to drop right on top of [Lionel] Messi and not worry about what is happening behind them. Ok, he'll drift away to the side. That's fine. He's less of a threat on the side than he is through the centre.

"After the inquest I told myself: 'When we play Barcelona next time in a Champions League final, I would have Jones and Smalling, or Smalling and Evans, right on top of Messi.' I wasn't going to let him torture us again."