Wrexham's pull managed to convince Premier League giants Chelsea and Manchester United into playing friendlies during their respective tours of the U.S. in 2023, and it was against the Red Devils where Mullin had to battle back from adversity for the first time for the club, suffering broken ribs and a punctured lung after colliding with goalkeeper Nathan Bishop. The injury was so severe that he had to remain Stateside while the rest of the squad returned home to allow it ample time to heal.
"I was trying to breathe in but nothing was happening," Mullin said in the aftermath of the incident. "I couldn't get air into my lungs. That's when I knew it was bad. In that struggle for breath, with my lips turning blue, I accepted that this could be it for me. That's how it felt. I couldn't breathe properly for a few minutes. I was thinking about my little boy, Albi. I hate being away from him and my partner Mollie for too long, but I had told myself it was only two weeks and that I'd be back home soon. It ended up being much longer, but I'm so thankful it wasn't worse."
Reynolds and McElhenney's undying love for Mullin saw them go the extra mile for the striker, helping him in his hour of need. He further revealed: "Ryan offered to fly my entire family out and Rob said I could stay with him in his Los Angeles home. I'm sure he has the room, but I was happy to stay out of the way. So they sorted an apartment for us instead. Rob visited me there before heading to Wales for our opening game of the season against MK Dons. I would have loved to be getting on that plane with him, but I had to stay there and rest. I haven't been able to walk for too long and every time I move it hurts."
Mullin sat out the rest of pre-season before making his return from the bench in September, but it took him a while to get back up to speed, scoring in only four League Two matches before the end of the calendar year. Wrexham went into 2024 sitting just outside the top three, which would secure automatic promotion for a second season running, and Mullin had yet to hit full stride by his own high standards. A slump in form saw him go seven games without a goal from January to the end of February, but when it mattered most, he stepped up.
With 14 goals across the final 13 games of the season, Wrexham raced into second place and were promoted to League One, Mullin their hero once more. He was about to add a 'super' prefix to that description, too.