In fairness the first loss, to Joe Schilling, came at the end of a close and competitive fight. But the other was a one-sided beating in China and made it look like Marcus had made a big mistake in switching codes.
Levin thought so; he publicly mocked that fight and said Marcus needed to take time off. Instead Marcus won last month's GLORY 20 DUBAI four-man Middleweight Contender Tournament to earn this Friday's title shot.
"When things aren't going your way and you lose it doesn't mean you are not good or not great, it is just a learning experience. It was just something you were missing or didn't do the way you were supposed to. So for every loss or mistake there is always a positive which can come out of it. If you focus on that positive it makes you grow," says Marcus, who insists the losses had no mental after-effects.
"It's about how you look at life and how you act when you are down and things don't go your way. There's two things you can do - you can let it defeat you, beat yourself up over it and tell yourself that you are not good enough and that you have failed, or you can take it as a lesson into making you greater, into making you stronger. [The latter] is what a real champion does."
In fact, Marcus says that the losses have been more instructive to him than any victory could have been. Prior to the tournament in Dubai he went out to Thailand and trained extensively with Buakaw Banchamek (formerly Por Pramuk), Buakaw being another fighter who crossed from Muay Thai to kickboxing.
"In fighting in particular, especially when you are a very competitive person, it will give you that push and that strength to fight more for your victories and to concentrate more," says Marcus.
"When you are winning all the time you get used to it. Winning is great, I love winning, it's my thing, but the losses that I have had... I can remember each one and how much they hurt. They remind me what I am doing and what I am working for. I am grateful for the losses because they have challenged me and reminded me who I am.
"Nobody is perfect, nobody is invincible, losing is nothing to look down on or be ashamed of, it's just about moving forward and looking up."
In Dubai, Marcus looked like a different animal. He seemed a lot more comfortable under kickboxing rules and fought a varied game, moving around with a mobile Wayne Barrett and having a close-range war with Jason Wilnis.
Fighting under Muay Thai rules he took wins over Artem Levin, Joe Schilling and Filip Verlinden among others, all of them among GLORY's very top names. Now he feels like he is in a position to recreate that success and says failure is not an option. Certainly the losses which preceded Dubai will not be on his mind.
"I am blessed and fortunate enough that I have the skill and capability to have worked my way up the ranks and win many world championships in Muay Thai throughout the years," he says.
"Now I have the opportunity to become the world champion of the biggest organization in my field. For me that is what I feel like my purpose is here on earth: not just to be a fighter but to be the best fighter, the champion.
"In that moment [when I am walking to the ring] I am going to be in the zone. I am going to be ready, focused. I am going to be reminding myself that I am the champion, to be who I am, to have fun and enjoy every moment.
"I am going to enjoy walking to the ring, I am going to enjoy having the fight and I am going to enjoy after the fight when I celebrate having the title. All of those thoughts will be floating around my head and I am looking forward to embracing whichever feelings come my way on fight night.
"It is about making sense of everything you dream about. It has to happen. I have to win."