WHEN Geelong defender Zach Tuohy started preparations for 2021, the simple message from his coaches was be prepared for anything.

The senior Cat could be needed as a full-time defender, he might be used on the wing, and spending time forward like he had in 2020 was again an option.

The only certainty was he needed to be across all lines and prepared for the last-minute changes Geelong's coaches have become comfortable throwing his way.

So it has proved this season, with Tuohy's time in defence ranging from as little as eight per cent (R5 versus North Melbourne) to as much as 100 per cent (four times).

He has played games almost exclusively on the wing (R19 versus Richmond) and others where little separates his time in defence, midfield and forward across the four quarters.

So what is it about Tuohy that makes this possible? Where other players want to be settled in a clear position, the 31-year-old almost thrives on the uncertainty of his role on game day.  

"It suits someone who prepares really well but is also pretty relaxed, and I don't think the game's pressures and stresses get to him a lot," backline coach - and former Geelong star - Matthew Scarlett told AFL.com.au. 

"He knows he's prepared well, he knows he can do it, and he backs himself in, so he doesn't mind getting told at the last minute you're in the back pocket, or you're on the wing.

"There's been a few last-minute adjustments with him this year and he just goes in and plays that role wonderfully well.

"He just says I've done it before really well and I'll do it again really well. That's the attitude and the mindset he has.

"His versatility and being able to adapt in all of these roles is really special."

Geelong's addition of triple-premiership Hawthorn wingman Isaac Smith this season has led to Tuohy's wing time dropping slightly from 44.7 per cent in 2020 to 36.5 per cent this year.

But he was back in the role prominently against Greater Western Sydney last Friday night, delivering in a big way to set up the Cats' semi-final win with a team-high 31 disposals and a game-high four goal assists.

It was Tuohy's best performance in 15 finals appearances, according to the Official AFL Player Ratings, and the first time he had amassed four score assists, combining that with 586m gained.

It was a performance that stood out to Scarlett, given everything that was at stake for the Cats, who now enter their sixth preliminary final under coach Chris Scott.

"It always carries more weight if they're able to deliver that on those big occasions," Scarlett said. 

"If we had lost, we were on a plane home, so there was a fair bit on the line and he was unbelievable really.

"He got a heap of the ball and he used it really well. It definitely ranks up there."

Tuohy's versatility, leadership and ability to use the ball well under pressure make him one of Geelong's most important players, and the team has missed him when he's been unavailable this season, losing three of those four games.

The Irishman's importance is amplified by the absence of injured gun defender Tom Stewart.

When the backline and wings are settled, however, Scarlett didn't rule out more time forward for Tuohy, where he has drifted occasionally this season to kick 11 goals. 

"He could be an amazing forward. He's got that leg strength, ability to pick the ball up clean, and kick the ball a mile," Scarlett said.

"He's played wherever the team has needed him, but he could settle into a forward role easily.

"He's certainly got some football in front of him, but which part of the ground that is we're unsure."