Ahead of UFC 227 which takes place Saturday night at the Staples Center in Los Angeles, bantamweight title challenger Cody Garbrandt brought up the issue of fighter pay earlier this week.

He claimed he was not 100 percent healthy to face T.J. Dillashaw when he defended his title against him at UFC 217 in November last year. However, with pay-per-view draw Georges St-Pierre headlining the event, he had no choice but to fight injured, as he would go on to suffer his first-ever loss after Dillashaw knocked him out in the second round.

If fighters in general were paid more for what they did even during the regular shows, Garbrandt says more of them wouldn't fight injured or even chase money fights as has been the case in recent years.

Garbrandt is not the only fighter to call for a higher pay. Lightweight contender Al Iaquinta is one who has regularly criticized the UFC for their pay structure while top middleweight Gegard Mousasi left the promotion last year for Bellator MMA, with the money he was offered by Scott Coker being a major factor.

With the UFC being sold for $4 billion two years ago, it's not surprising to see more and more fighters ask for higher pay and get a piece of the pie, and given how it's become a topic of discussion again, here's a look at the top 25 earners in 2018 so far.

The numbers below are based on official as well as in some cases, estimated figures. They also include bonuses and additions or deductions due to a fighter missing weight. Pay-per-view points are not included.

Stipe Miocic — $1,350,000 — UFC 220 and 226 Daniel Cormier — $1,000,000 — UFC 220 and 226 Alistair Overeem — $860,000 — UFC 225 Mark Hunt — $765,000 — UFC 221 Frankie Edgar — $615,000 — UFC 222 and Atlantic City Robert Whittaker — $610,000 — UFC 225 Francis Ngannou — $600,000 — UFC 220 and 226 Derrick Lewis — $570,000 — UFC 226 Yoel Romero — $545,000 — UFC 221 and 225 Khabib Nurmagomedov — $530,000 — UFC 223 Ronaldo "Jacare" Souza — $520,000 — UFC Charlotte and 224 Donald "Cowboy" Cerrone — $510,000 — UFC Austin and Singapore CM Punk — $503,500 — UFC 225 Cris Cyborg — $500,000 — UFC 222 Dustin Poirier — $490,000 — UFC Glendale and Calgary Lyoto Machida — $490,000 — UFC Belem and 224 Luke Rockhold — $485,000 — UFC 221 Junior Dos Santos — $415,000 — UFC Boise Jeremy Stephens — $395,000 — UFC St. Louis, Orlando and Calgary Colby Covington — $380,000 — UFC 225 Rafael Dos Anjos — $380,000 — UFC 225 Volkan Oezdemir — $350,000 — UFC 220 Fabricio Werdum — $340,000 — UFC London Vitor Belfort — $315,000 — UFC 224 Sage Northcutt — $310,000 — UFC Austin and Boise

There are many things that can be observed from the list.

For one, there are just two fighters under the age of 30 who are in the top 10 earners and that's UFC middleweight champion Robert Whittaker and lightweight champion Khabib Nurmagomedov, both of whom were main event headliners this year.

MMA veterans Alistair Overeem, 38, and Mark Hunt, 44, earned $860,000 and $765,000 respectively just from appearing once — the highest figures a fighter has earned from a single event.

Former WWE star CM Punk, 39, competing in just his second professional fight, banked just over half a million dollars for his loss against Mike Jackson. Jeremy Stephens meanwhile, required three appearances as well as performance bonuses to crack the top 20 with $395,000 in earnings.

The UFC payscale has definitely improved in recent years but there is considerable work to be done if the Las Vegas-based promotion wants a happy roster.