Niall Horan's trip to Chelsea Football Club had to be kept a secret, says Jose Mourinho.

The One Direction heart throb has been given use of their recovery unit following major knee surgery, and the club's manager has admitted it was a struggle to hide what was happening from the band's loyal fans.

Speaking to The Sun newspaper, he said: ''I was worried for a while because I thought, 'Nobody can know that Niall is at Cobham - we'll have thousands of girls at the gates!'

''Niall had seriously big surgery - an injury any football player would be scared of suffering. He really needs a good medical department.

''My kids are big fans but they haven't been to the training ground to see him - he has a lot of work to do.''

Jose's children are the reason behind Niall's connection with the club, prompting him to agree to the arrangement.

A source previously said: ''Niall has been welcomed into the club as if he's a Chelsea star himself.

''It's the best possible place for him to get the rehab he needs on his knee because he needs to be fighting fit for the band's stadium tour later this year.''