John Obi Mikel established himself as a key player for Chelsea between 2006 and 2017.   

The midfielder won it all at Stamford Bridge as he picked up two Premier League titles, three FA Cups, one League Cup, the Champions League and the Europa League. 

Not bad at all. But after 11 years in London, Mikel was told his contract wouldn't be renewed after the 2016/17 season so instead, he sought a new challenge elsewhere. 

In January 2017, he signed for Tianjin Teda FC in the Chinese Super League on a free transfer. 

When he moved, the CSL was in the middle of signing some very big name players for huge salaries and Mikel joined the likes of Oscar, Hulk, Alex Teixeira and Paulinho in Asia. 

The promise of a massive paycheck has continued to attract more players to China and the league has begun to seriously appeal as a destination for big names to play. 

But according to Mikel, who's been there and done it - and since returned to England to play in the Championship with Middlesborough, the grass isn't greener on the other side of the world.  

He's sent a warning to any footballer that is tempted to move to the CSL and has even suggested that anyone under the age of 30 would 'regret' that decision. 

"It was two years of a huge culture shock," the Nigerian international told The Telegraph.

"The food was a problem, the lifestyle, the style in which everything was done. 

"When you have been at a club like Chelsea in the Premier League, for 11 years, it was very hard to adapt to how things were done. It isn’t at the elite level, let’s put it that way."

Mikel went on to explain why his move was such a shock and claimed that even though the league wants to grow, it is a long way behind. 

"The pitches were poor, stadiums are poor, and the medical facilities were not what I was used to," he continued.

"I’m not saying it’s all the Chinese clubs, some of them are quite professional, but the one I was at, it wasn’t as professional as it should have been. It became tough for me almost straight away.

"The standard of football, it’s not even Championship standard. I realised that very quickly. It’s a league that wants to grow, they are putting a lot of money in, but it is a long way behind."

Ouch, that's a pretty tough assessment from Mikel, who finished his interview by offering advice to any player contemplating a move. 

"My advice to anyone thinking about going, is have a long think about it. You have to go at the right time.

"I certainly wouldn’t say to anyone under the age of 30 to go there. They will regret it if they do."