Tottenham Hotspur manager Mauricio Pochettino has said the club are "working so hard" to tie down Christian Eriksen to a new contract amid speculation linking him with a move away from the club.

According to the Express (h/t the Daily Mirror's Tony Banks), both Paris Saint-Germain and Real Madrid are interested in the Denmark international, whose contract with Spurs expires in the summer of 2020.

In addition, Tuttosport (h/t MailOnline's James Ayles) have reported Juventus are admirers of Eriksen.

When asked about the speculation on Thursday, Pochettino said the club are making a big effort to get Eriksen to commit to fresh terms.

"He [Eriksen] knows, and we know what we are doing," the Tottenham boss told reporters. "We are working so hard. The club is trying to take the best decision. Christian will take the best decision. I am not worried, but I prefer he is going to sign a new contract and stay a long time with Tottenham."

Here's more of what the Spurs manager had to say on the matter:

The midfielder arrived at Tottenham from Ajax in 2013, and in his five years in north London, he's progressed to become one of the most creative players in English football's top flight.

Last season he showed that not only is he inventive enough to make chances for team-mates, but he can also get on the scoresheet:

It's why the ticking clock on Eriksen's contract will be such a big concern for Tottenham supporters, as players who possess that kind of productivity are hard to come by.

While Pochettino signed a new contract with the club in the summer and Dele Alli recently agreed fresh terms until 2024, Eriksen isn't said to be quite so keen to sign on for a few more years yet.

Gary Jacob of The Times said the Dane has concerns about the "manager's future, transfer budgets, winning silverware and qualifying for the Champions League."

Following the FIFA World Cup—where Eriksen was the key man for Denmark—some injury issues and the growing doubts over his contract, perhaps it's not a surprise that the Tottenham man has been a little below his best so far this season:

However, the 26-year-old got a couple more games under his belt on international duty, and he should be approaching full fitness ahead of the clash with Chelsea this weekend.

Tottenham are blessed with a number of attacking midfielders in the form of Alli, Heung-Min Son, Lucas Moura and Erik Lamela. Yet none are as incisive on the ball as Eriksen, nor able to knit play together in the final third or provide a consistent threat from set-piece situations.

While Pochettino is putting on a calm front, the longer this contract wrangle rumbles on, the more stressed he will surely be about keeping one of his key men at the football club.