The 19-year-old singer, who performed Adele's 'Make You Feel My Love' on the ITV contest, was apparently on the verge of pulling out due to injuries sustained in a football match.
An apparent BGT insider told The Sun: "Sam has been told to rest and take it easy. Everyone on the show is hoping he is going to be okay to continue."
Addressing the reports on Twitter this afternoon (April 20), Kelly assured fans that his predicament "won't stop [him] playing footy let alone singing".
"I did hurt my ribs playing football but they are ok," he explained. "I've just replaced them with coathangers for the time being...wasn't anything major tho!!"
He later told a concerned follower: "I definitely won't be pulling out even if my ribcage is hanging out."
Kelly recently admitted to Digital Spy that he was "scrounging around for money" before appearing on Britain's Got Talent.
BGT continues tomorrow (April 21) at 8.30pm on ITV1.
> 'Britain's Got Talent' Sam Kelly: 'I couldn't do X Factor'
Watch Sam Kelly audition for Britain's Got Talent below: