Sir Alex Ferguson's decision to launch a pre-season attack on Chelsea was nothing new to the Premier League.

The United manager is well known for his bitter assails on his closest rivals so it is perhaps his praise for Arsenal that is most shocking.

When Arsene Wenger arrived in England, Ferguson was the dominant force in club management. Arsenal were tipped to struggle under the unknown Frenchman but his quest for footballing perfection turned the club into champions, launching an astringent battle for supremacy at the summit of English football.

The rivalry erupted throughout the teams, Patrick Vieira and Roy Keane at the heart of every thundering tackle and disputed decision, a microcosm of their touchline mentors.

But as the time of Vieira and Keane passed, the heat between Ferguson and Wenger has cooled with Chelsea providing the perfect sweetener to the sour relationship.

When Jose Mourinho arrived at Chelsea, Arsenal were unbeatable and United were seething. Wenger had achieved what Ferguson had thought impossible and the Old Trafford boss was clearly riled by the Frenchman's undisputed achievement.

But the 'Special One' was more than keen to stir his own flavour into the sumptuous mix and, backed by the millions of Roman Abramovich, he went on to lift two Premier League titles, much to the annoyance of his jealous peers.

But Ferguson, used to his one-man feud with Wenger, reacted instinctively, channelling his hatred from North London to South West. Rather than ignore the presence of Wenger, the Scot has instead sought to ally the Frenchman against the growing threat of Chelsea. 

Ferguson's admissions at the beginning of last season that Thierry Henry's absence would be less keenly felt than anticipated, proved right. Arsenal set the league ablaze with a display of fluid and exciting football and some would argue that injuries and a lack of experience prevented them for lifting the title. Ferguson would appear to agree.

It was only when the heat of the Old Trafford battle last April had dispersed and Manchester United emerged with a priceless 2-1 victory over Arsenal that Ferguson revealed his true feelings towards Wenger. Frankly admitting that Arsenal were "magnificent", few would have expected such an honest assessment of the game.

The pre-season build-up has brought little difference. Ferguson has already stated his belief that Arsenal may have won the league if injuries had not hit during February and said the Gunners' achievements were "understated" – heady praise indeed towards one of his fiercest rivals.

His attack on Chelsea, labelling them ''old'' and having reached a "plateau", reveals that Ferguson believes them to be the polar opposite to Arsenal. Young and developing are adjectives more commonly associated with the Gunners.

Wenger has also responded in kind, backing his rival over Real Madrid's candid pursuit of Cristiano Ronaldo, but it remains to be seen how long the ceasefire will continue.

Few would bet that Ferguson would have been so complimentary had Arsenal beaten United 1-0 at Old Trafford and gone on to win the league - and few would expect Wenger to shed a tear if Ronaldo swapped Manchester for Madrid.

But as the truce between Wenger and Ferguson continues, it leaves a vacuum in the war of words. And filling it may be Luiz Felipe Scolari's biggest chance of upsetting his emotional rivals as he looks to find his place at the table of the Premier League's elite.