Shaun Grigg is facing an uphill battle to be fit for Richmond’s season opener against Carlton, reports AFL.com.au’s Mitch Cleary.

Grigg failed to train on Thursday, with the Tigers labelling the injury as “medium-term”.

In comparison, Josh Caddy (ankle) and Tom Lynch (knee) have been listed as “short term” by the club’s medical staff, with an expected return 1-2 weeks away from full training.

Since crossing to the Tigers from Carlton in 2014, Grigg has played 171 of a possible 184 games, with a hamstring complaint in 2014 his only major injury.

Grigg has 28 days to prove his fitness for the opening game of the AFL season against Carlton at the MCG on Thursday 21st March.