Nowadays an ultra-reliable defender, rarely beaten by his man and ruthless on the counter-attack thanks to his piercing kicking skills, Guerra's importance to Hawthorn is often understated.
He won plaudits for the professionalism with which he attacked his rehab after straining a hamstring in round 23 last season, and for his selflessness in ruling himself out of Grand Final contention after doing all he could to come up.
The 30-year-old's attitude through that testing time showed in stark detail how far he has come since his formative years in the League, starting as a teenager at Port Adelaide in 2000.
"In the early days I wasn't the most professional footballer," Guerra told AFL.com.au in the lead-up to round one and the start of his 14th season.
"I just got sucked in a little bit, as a lot of young footballers do.
"It took me a bit longer to learn."
The Hawks' fitness boss Andrew Russell, who Guerra credits as a major influence on his long career, was at the Power during the left-footer's first foray into the big time.
He recalled a young man with talent, but who failed to grasp the link between on-field success and off-field behaviour.
"We really liked him; we liked his competitiveness and we liked his spirit," Russell said this week.
"But he was a country boy who came into a foreign world, and probably didn't deal with it very well in the early days.
"He certainly didn't respect recovery and how important it was.
"So we'd see some really good stuff from him, and then he'd break down and get injured, or he'd get sore or he'd get tired.
"He got to the point where as much as we liked the bloke and knew what he could do, he just didn't seem to be getting it."
Guerra managed 65 games in four seasons at Port Adelaide, playing mostly as a forward, before asking for a trade back to his home state of Victoria and being dealt to St Kilda.
Yet he lasted only two seasons at the Saints, who, aware of his potential but unimpressed with his lack of consistency, delisted him at the end of 2005.
His career at a crossroad, Guerra's hopes of an AFL resurrection rested with Hawthorn, where coach Alastair Clarkson, who had worked with him at both Port Adelaide and SANFL club Central District, weighed the merits of giving him another chance.
Russell, having also crossed to the brown and gold, was asked for his input.
"Brent was fortunate in that he had a couple of weapons that he was very, very good at," Russell said.
"One, he's a good bloke, and two, he's an extremely good kick, and he's such a strong player.
"My feedback was that it was high risk, high reward.
"I thought if we could get his lifestyle right and his recovery and his body right, then he'd be a good chance to play a lot of footy.
"What I wasn't sure about was whether he was going to buy into that."
The Hawks decided to take the discarded Saint in the pre-season draft, and Russell knew almost straight away it was the right call.
"When he came to Hawthorn, he came as a different person," Russell said.
"For the first time since I'd known him he had his eyes wide open, saying, 'Right, now I'll actually listen. Tell me what you want me to do and I'll listen.'
"He's probably come as far as any player I know in terms of professionalism, and he's become one of the better players that I've worked with in terms of reading his body."
Working with Russell, Guerra identified his ideal weight, skinfold measurement and training loads, and he has stuck rigidly to all three for the past several seasons – a significant factor in his durability.
Fit after a consistent pre-season and with just 14 games until 250, the hard-nut now has one eye on the rarely attained mark, which once seemed as fanciful for him as the idea of ever shirking a contest.
"I probably won't play all 14 games straight up, but if I can get to 250 I'll be very happy with that achievement," he said.
"At one stage I didn't think I'd get to 100."
Brent Guerra is a defender in AFL Fantasy. He averaged 76.5 points in 2012. Register your team at our AFL Fantasy hub.
