Sunderland’s shock win at Stamford Bridge has sent shockwaves rippling through English football. How could a side that are a usually so brutally clinical be out-played and out-classed in their own backyard?

In many ways it would be unfair to be overly critical of Chelsea’s display because it would take the shine of a Sunderland performance which was arguably their best ever in the Premier League. Steve Bruce’s side were nothing but superb, not only in their effort and application but their ruthlessness too.

But as good as Sunderland were, Chelsea were equally poor. Carlo Ancelotti will put the blame at injuries to the likes of John Terry, Frank Lampard and Alex, as well as the suspension of influential midfielder Michael Essien.

In years gone by though a Chelsea squad would have easily been able to cope with an injury crisis, and you have to question the clubs decision to constantly let players go without replacing them? Yes they are trying to cut costs, but is it worth seeing the team suffer?

The Chelsea squad is drastically ageing, and in the next few years they will need to invest heavily in their playing squad if they are to remain competitive with the likes of Manchester City, because if they don’t Roman Abramovich’s dream of a Chelsea empire will rapidly slip away.

When the Russian arrived in West London there was an intense period of investment in to the playing squad, but this slowly decreased and over the last few seasons the incomings transfers at Stamford Bridge have been few and far between.

Deco, Michael Ballack, Joe Cole and Ricardo Carvalho were the big name departures from Stamford Bridge in the summer, and no matter how strong the squad that won the double was last season was, no side can lose that sort of talent and expect to be as strong.

The Chelsea bench on Sunday demonstrated Ancelotti’s problem with only Salomon Kalou boasting any real experience in the Premier League. While the Italian must be praised for bringing through young players and giving them a chance, it is highly unlikely that this will bring the success that Abramovich demands.

Personally I still think Chelsea will win the league this season, because their first team is so strong, but if they continue to have bad luck with injuries there may be plenty more shock results to come. Chelsea were once the team with best squad in the league, this simply isn’t the case anymore.