GEELONG, AUSTRALIA - MARCH 07: Gary Rohan of the Cats is congratulated by Tom Hawkins of the Cats after kicking a goal during the 2019 JLT Community Series AFL match between the Geelong Cats and the Essendon Bombers at GMHBA Stadium on March 07, 2019 in Geelong, Australia. (Photo by Scott Barbour/Getty Images)

Geelong duo Gary Rohan and Sam Simpson appear set to miss the Cats' opening round clash against Essendon due to differing injuries.

Having failed to lace the boots in either of Geelong's pre-season contests against Richmond and Gold Coast, Rohan will enter his 13th AFL campaign underdone after being forced to sit out with a back complaint.

Speaking with The Geelong Advertiser on Thursday, Geelong Head of Football Brad Lloyd claimed that while the club would take a tentative approach to the 30-year-old's rehabilitation program, Rohan was β€œon the improve.”

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β€œ[We] will give him [the] time he needs and monitor as he increases his loads,” Lloyd said of the forward who also underwent minor knee surgery over the summer.

GEELONG, AUSTRALIA - MAY 18: Gary Rohan of the Cats celebrates a goal during the round nine AFL match between the Geelong Cats and the Western Bulldogs at GMHBA Stadium on May 18, 2019 in Geelong, Australia. (Photo by Darrian Traynor/AFL Photos/Getty Images)

Having broken through for four appearances across the course of his fourth season at Kardinia Park, Simpson remained a live possibility to add to his tally of 19 AFL games later this month.

However, after succumbing to a head knock during a recent training run, the 23-year-old's strides to stay in Chris Scott's best-22 have been scuppered.

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With the league stipulating that players who have sustained concussions will be required to sit out for a mandatory 12-day period, Simpson is now a certainty to miss Geelong's Round 1 date with the Dons.

This setback is just the latest in a long line for the father-son selection who has failed to feature in more than nine games in a year since debuting in Round 15 of the 2017 season.

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Geelong will make the short trek up the highway without the injured pair to face Essendon at the MCG on Saturday, March 19.