Aerosmith star Tom Hamilton has sparked fresh concerns for his health after sitting out of the band's Monsters of Rock show in Brazil on Sunday (20Oct13).

The rockers performed in Sao Paulo, but Hamilton's place onstage was filled by David Hull, who has often replaced the bassist during his recent heath battles and cancer treatments.

Reports suggest that Hamilton was too ill to perform.

The rocker was diagnosed with throat and tongue cancer in 2006 and missed the band's Aerosmith's Route of All Evil Tour. His cancer returned in 2011, but he has since been treated and well on the road to recovery, although a health issue forced him to retire from the band's Australian tour earlier this year (13).