TOM STEWART'S last-minute heroics on Thursday night showed why he's quickly become indispensable to the Cats, coach Chris Scott says.

With Geelong needing to protect a two-point lead against Port Adelaide with a minute to go, all eyes fell on star Robbie Gray as he waited underneath a high kick in the forward 50.

Gray had only defender Stewart for company, and Cat midfielder Mitch Duncan admitted he was worried.

"[We] probably left Tom Stewart out to dry a little bit," Duncan said after the match.

But Stewart was unperturbed, forcing Gray to spill the mark before pouncing on the ball until help arrived.

Such was the 24-year-old's coolness in the moment that when his teammates patted him on the back after the siren and said "great contest", Stewart simply asked: "which one?"

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Duncan didn't need reminding what his teammates were referring to.

"Robbie [Gray] is obviously a great one on one player but Tommy Stewart puts the work in week in week out [and] that is what he is in the team to do," Duncan said.

Scott described Stewart, a South Barwon product who played well for Geelong's VFL in 2016, as a "local boy made good".

"He has got a lot of talent so I don't want to underrate that but I don't think he was that committed to a future in footy as an 18 or 19 year old," Scott said.

"As soon as he decided it was what he wanted to do, he has committed himself really well

Stewart played on taller opponents than Gray for most of the night, picking up 19 touches and taking four marks but it was his effort to neutralise Gray when the game demanded he do so that won plaudits.

"We need to bring in players who can do the job straight away, so that contest epitomised that," Scott said.

• Match centre: full stats and highlights from Thursday night's thriller