But according to the UFC bantamweight, that was nearly the case.
For the first time in two years, McDonald (16-3) is healthy enough to book a fight. Ideally, he'd like to make an appearance in 2015, but it might not happen until next year. The former interim title contender has been sidelined since 2013 with hand and wrist injuries, but after finally receiving proper diagnosis and undergoing the necessary procedures, he believes the issues are behind him.
Nevertheless, McDonald admits there were times during the layoff that he strongly considered walking away from professional fighting for good. And for reasons not related to his health.
"I think everyone has expectations of being a professional athlete, and it's just not exactly what you expect," McDonald told ESPN.com. "It wasn't very fun after a while. I didn't feel any passion for fighting or the people around me."
How does a 20-something-year-old phenom lose his passion for MMA? McDonald says it can be traced to a matter that he never thought he'd have to focus on: Money.
McDonald was two months removed from his 20th birthday when he made his UFC debut in March 2011. The California native was one of the best prospects in the sport and in just his third UFC appearance, he was booked to fight former WEC champion Miguel Torres.
The fight took place at UFC 145 in April 2012. McDonald knocked out Torres in spectacular fashion just three minutes in. His contracted pay for that fight was $8,000 to show with an $8,000 win bonus. According to public records, Torres disclosed pay was twice as much.
McDonald says he understands how compensation in this sport works and that Torres, at that time, was the far bigger name. But the discrepancy in what each was paid had started to eat at him. He poured himself into that training camp and achieved a perfect result, only to return home and have financial concerns.
"I'd say things started to get complicated after the Miguel Torres fight," McDonald said. "Money was something I've never wanted to focus on, but when I look around and see people who I'm beating making a lot more than me, I started to feel angry and resentful.
"I knocked out Torres and I barely made any money. That's when that frustration started and it just makes you not enjoy your job. You feel underappreciated and cheated. You don't want to go out and fight the best fighters in the world, then go home and wonder if you can pay your bills. You start to say, 'Something's not right now. I'm angry.'"
McDonald says the promotion took care of him after a loss to Renan Barao for the interim title in February 2013, but the majority of earnings in his UFC career have come through Fight Night bonuses. His disclosed pay in his last fight, the loss to Faber, was $17,000. Faber, one of the more popular fighters in the sport, earned a disclosed purse of $200,000.
Now 24, McDonald says he doesn't believe the UFC has mistreated him, but in a weird way, he's been a victim of his own success. As he prepares to return to his professional career, he's made significant changes to his managerial arrangement.
Like other fighters have done since the UFC's Reebok deal, McDonald has eliminated the traditional fighter, manager relationship, as there is less of a need to secure sponsors. He's appointed Richard Goodman, his former matchmaker at Tachi Palace Fights, to handle individual fight negotiations. Until he's contractually guaranteed more money, McDonald says he may pass on a certain matchups.
"When I joined the UFC, it was, 'You're the youngest fighter in the UFC! No one as young as you has ever fought for the title! You want to do it?' It was like, 'Uh, yeah.'" McDonald said. "Now, there is a lot of stuff I have to correct.
"It's a problem I made by not getting paid well and fighting the best in the world. It's a difficult situation but I think we're going to get through it. There's no way I'm going to fight top guys for the pay I'm getting, especially when they're getting so much more than me.
"I don't think it's as cut and dry as, 'Oh, I'm not fighting this guy.' I'm not looking for easy fights. One thing I see now is that if you're talking to a businessman and you ask for something reasonable, usually they'll be like, 'OK, let's work something out.' If the UFC wants me to fight these great guys like Faber, it's not like I'm looking to play hardball. But yeah, I wouldn't want to fight him with the pay I'm getting now. So, maybe it turns into a contract renegotiation. Maybe it's, 'Let's hold off and not take this fight right now.' Maybe it's, 'Well, can we get a little more guaranteed money for this fight but keep the same contract?" I don't know what it's exactly going to be, but I have to be taken care of."