Rio Ferdinand believes English clubs' failure in the Champions League in recent years is due to the world's best players no longer playing in the Premier League.

The former Manchester United defender - who played in three Champions League finals, winning the trophy in 2008 - believes the Premier League is the 'most entertaining' league in the world.

But with Manchester City becoming only the fourth English side to reach the quarter-finals of Europe's premier club competition since 2012 on Tuesday, Ferdinand believes the loss of the likes of Cristiano Ronaldo, Luis Suarez and Gareth Bale has left Premier League teams without the tools to challenge on the biggest stage.

Rio Ferdinand does not believe the Premier League has any of the world's best players at the moment

Ferdinand (second left) won the Champions League with Manchester United in 2008

But the likes of Ferdinand's former team-mate Cristiano Ronaldo have now left the Premier League

'In those days we had teams that were conditioned to go into tournaments and go deep into tournaments,' said Ferdinand on BT Sport ahead of Manchester City's clash with Dynamo Kiev.

'[The] mentality was about just getting through the first period of the tournaments and taking each game as it comes.

'[In the Champions League] there's a consistency among these teams within the leagues they play in, they can go 20 games on a winning streak drawing a couple and maybe losing one.

'I think back then the best players in the world, there were some in this country. At the moment there aren't any.'

Ferdinand said he 'loves' Sergio Aguero and that the striker would score goals for any team in the world

But the former Manchester United defender doesn't rate the Argentine among the 'best in the world'

While Ferdinand doesn't rank any of the Premier League's top talent among the best in the world, the former England defender singled out Sergio Aguero, professing his 'love' for the Manchester City striker.

'I love Sergio Aguero. The last three or four years of my career in the Premier League he was the hardest striker I played against.

'He's quick, he's got a low centre of gravity, he's strong, he'll go off both sides - left or right, doesn't mind - and he's a devastating finisher when's he's in front of goal and I think he could play in any team in to world and he'll do this, he'll score goals.