It was reported on Tuesday that as many as six AFL players earned a seven-figure sum in 2021 - a significant portion of the $13.4m salary cap.

But while fans and media alike love to debate who is worth what, it's not as simple as ranking the six best players in the competition and paying them accordingly.

In addition to what a player offers on the field, there are a number of factors that determine just how much they're worth - age, whether they're on an upward or downward spiral, other star players to pay at their club, whether they're in their 'home' state and when they signed their contract, to name but a few.

Here, we look at the players reported to be on $1m or more in 2021 - Dustin Martin, Lance Franklin, Jeremy McGovern, Brodie Grundy and Nat Fyfe - plus a couple tipped to reach that mark in 2022 - Christian Petracca and Tom Lynch - and determine whether it's money well spent ...

5. Brodie Grundy

This is an interesting one.

Brodie Grundy was, along with Max Gawn, by far and away the best ruckman in the AFL when he inked a seven-year deal to stay with Collingwood at the start of 2020.

He had over 1000 hit-outs in 2018 and 2019, averaging over 20 disposals in both seasons and polling 17 and 23 Brownlow votes respectively.

A South Australian, there was a genuine chance Grundy would look to go home when his contract expired - not to mention almost every club in the competition making his signing a priority.

To keep him, Collingwood simply had to come up with a mammoth offer.

And they did.

However, it's been anything but smooth sailing since.

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Grundy's form has dropped considerably since inking the seven-year deal.

Don't get me wrong, he's still an above-average ruckman - but he hasn't been anywhere near the dominant player he was in 2018 and 2019.

Melbourne premiership captain Gawn has pulled right away as the best ruckman in the competition, while Grundy is flat-out holding the No.2 position.

Collingwood's form has reflected Grundy's too.

The Pies were a kick away from winning a premiership in 2018 and were again beaten less than a kick in the 2019 preliminary finals.

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However, the club just fell into the finals in 2020 - although they did record an excellent win in Perth in their elimination final - before slipping to second-last on the ladder in 2021, with long-time coach Nathan Buckley leaving the club mid-season.

Grundy's big-money contract is also said to be a key factor of the disastrous 2020 trade period, which ultimately saw Rising Star winner Jaidyn Stephenson traded to North Melbourne, gun midfielder Adam Treloar traded to the Western Bulldogs and running machine Tom Phillips traded to Hawthorn.

It is said that the Pies are paying part of the contracts of all three players, and the trade period ultimately led to list manager Ned Guy leaving the club mid-2021.

It's hard to defend any contract which has caused so much turmoil, especially when the player has underperformed since signing it.

However, that's not Grundy's fault and, if he can get himself back to being a standout ruckman - and player - in the competition over the next few seasons, then the big money could still justify itself.

Verdict: The jury's out right now, but we'll know by the time his contract expires in 2027 - and potentially much sooner.