Brisbane Broncos star centre Herbie Farnworth will reportedly be fit to play Sunday's NRL grand final despite suffering an injury at training on Tuesday.

Training with the grand final bound Broncos at Red Hill, Farnworth reportedly left the field with what appeared to be a hamstring problem and failed to complete the session.

The Broncos have since clarified however that the injury isn't in the hamstring, and he will be fine to play on Sunday.

The news is a lucky break for the Broncos given even minor hamstring injuries generally rule players out for at least a fortnight.

Regardless, it does mean Farnworth's preparation for the biggest game of the year against the Panthers will be hampered throughout the remainder of the week.

Farnworth will have a tough assignment in the grand final attempting to slow down the dangerous edges of Penrith's attack which ran up plenty of points against the Melbourne Storm in last weekend's preliminary final.

Farnworth's influence over Brisbane's attack can't be understated either - the international representative player scored a double in the Broncos' own preliminary final win over the New Zealand Warriors and has had a wonderful season, scoring 15 tries in 25 games, making 128 tackle breaks and averaging 167 metres per game.

It's unclear how Brisbane would replace Farnworth if he was to be injured, although the options will likely be either Deine Mariner, or a shift for Jesse Arthars from wing to centre with Corey Oates joining the run-on side.