Louis Tomlinson is struggling with a sore knee on tour.

The One Direction singer is worried his injured leg will get in the way of the boyband's typically energetic performances during their 'Take Me Home' arena world tour.

Ahead of the gang's gig in Belfast, Northern Ireland, on Monday night (11.03.13), Louis tweeted: ''Knee hurts... Ah well f**k it . I apologize if I'm not jumping around on stage as much, stupid knee ! #kneedtogetbetter (terrible joke) (sic)''.

The teen heartthrob's mother Joanna also weighed in on his crisis, posting: ''My baby first born has a poorly knee! Xxx.''

However, Louis is soldiering on through the mammoth tour and gave a strong performance on stage, before jetting off to Dublin ahead of One Direction's sold-out show tonight (13.03.12).

Bandmate Niall Horan also tweeted support for his pal, writing: ''Belfast! That was an amazing, poor aul Tommo an his knee! Hahaha! Great week up here ! See ya soon! #1DTMHT (sic)''

The UK and Ireland leg of the boys' tour culminates on April 19 at Manchester Arena, after which they will head to France and mainland Europe.

Canadian singer Justin Bieber thanked the kind-hearted 'One Way or Another (Teenage Kicks)' hitmakers yesterday for defending him after his controversial visit to London last week, during which he showed up almost two hours late for his concert at London's The O2.