Silvestre signs for Arsenal - how?

How indeed, when in 2007 Manchester United chief executive David Gill stated:

"On Monday night we received a written offer and it was a significant offer. We've rejected that - yes, because it's Liverpool. We wouldn't sell to Liverpool, Arsenal, Chelsea. We have relayed that to the agent. We have told him that in no uncertain terms."

This was in reference to the Gabriel Heinze transfer to Liverpool, eventually the Argentine was allowed to go to Real Madrid after a protracted transfer dealing. The rivalry between United and Liverpool is well documented, summed up by the famous Alex Ferguson statement of intent "I want to knock Liverpool off their F****** perch".

Arsenal have signed the 31 year old French defender for an undisclosed fee, manager Arsene Wenger said of the signing: "We have a strong squad but a young squad.

"Mikael's versatility, experience and calibre will provide the extra depth we need to reinforce our challenge for honours this season.

"His defensive adaptability will serve us well, and it's a big plus that Mikael has top-level experience and a great understanding of football in the Premier League."

We can only assume this means not only did United consider Silvestre surplus to requirements, but not even good enough to significantly strengthen one of their "big four" rivals.