'They are buying the title' was a criticism often levelled at Jose Mourinho's Chelsea when the Portuguese manager took over following Roman Abramovich's revolution in 2004. Of course Mourinho filled the void after Claudio Ranieri's final season in charge, but nevertheless at the time the Blues were criticised for buying all their success.

Now it seems that the shoe is on the other foot, with Blues boss Mourinho claiming that their Premier League rivals, Man United, Man City and Liverpool are attempting to 'buy the title'

However Abramovich will be all too aware - money can only do so much - that you need the right man in charge, highlighted by the fact last term yielded the Londoners' first Premier League crown since 2009/10 despite major investment through the intervening spell.

That is not to say that having money doesn't help; it does of course and without the Russian's sizeable investment Chelsea wouldn't have won four Premier League titles. However without Mourinho, and still with pots of cash, they would, possibly, only have one. So these clubs spending big should be careful, as cash doesn't guarantee success.

Furthermore Mourinho has not made any major signings after last year's success, despite the heavy investment of their rivals.

Is this really the right decision?

Mourinho said speaking after his side 1-1 draw with PSG: "Now, they are buying the title. All of them, they are buying the title.

"It is up to us to be strong and to fight them and, obviously, to try and win it again, even without the big investments."

The interesting part of that quote is his revelation that there won't be money to spend and he will have to win it again without the investment he's been so used to, which will be difficult. It is notoriously tricky to win back to back titles with investment, let alone without - only two teams have retained the Premier League title: Chelsea under Mourinho in 2005-06 and Man Utd who have retained the title on six occasions. No side has retained the title since the 2008/09 season, it is indeed getting tougher to do it.

Usually it's said you have to invest after winning otherwise your rivals will inevitably catch up and pass you. It looks like we will find out if this is true with Chelsea this season.

Of course Chelsea have signed Radamel Falcao, who could well turn out to be a fantastic addition if he finds his old self again, but it's not big investment in terms of fee (he's on loan). He will cost a fair chunk in terms of salary, though. Other than that, the arrivals door at Stamford Bridge hasn't seen too much action, but I think Mourinho is right not to spend big.

This is for two reasons, the first being he is going to try and bring and introduce a group of talented youngsters like Ruben Loftus-Cheek to the first-team, which will be like making new signings. Heavy investment would of only mean this talented group wouldn't get their chance.

The second reason is that the Blues' squad is quite unique. Jose has a relatively restricted pool of stars and at times last season he relied on the 36-year-old Didier Drogba to lead the line, but this small squad is incredibly strong. There is enough depth in every position, and there is real quality in every area. Obviously Petr Cech and Filipe Luis leaving will damage those areas, but throughout the rest of the unit there's is a good blend of experience, youth and quality.

Take the centre-backs, Terry and Cahill are a great partnership but if injuries occur there is the powerful Kurt Zouma waiting in the wings, who is more than capable. Even Ivanovic could fill in with Ramires switching to right-back, too.

Obviously this is an example, but because of the talent and versatility his players possess, Mourinho has already got a balanced squad that is gelled together - far more valuable than an expensively assembled squad that is not balanced and perhaps more importantly isn't gelled together.

The Blues' rivals will need to get things settled, which could take time and affect form for a while. Mourinho will not have such a worry and for that reason his squad is better off for it.

Who knows if the Chelsea boss is right, time will tell but who are we to question the man who has done it before and will surely do it again?