Both Gillian Robertson and Taila Santos had bouts planned for this month, though the two weren't originally matched up against each other.
With the matchup changed, Canada's Robertson (9-4) and Brazil's Santos (16-1) will now clash in a flyweight contest on Saturday evening at UFC Fight Night 183 inside Las Vegas, NV.
The 25-year-old Robertson was previously booked to square off against Andrea Lee last weekend at UFC 256 until Lee pulled out of the card due to injury.
Even though Robertson has shifted from stepping in for a ranked opponent to fighting a relatively new UFC face, she insisted she never hesitated about jumping into the contest.

"I was prepared to step in, and I'd invested too much work into this camp to walk away," Robertson told MMA Empire during an interview.
"If I'm ever going to become champion, I need to be capable of beating any woman in this division, so whoever ends up across from me, I'm taking that fight."
Santos, 27, was originally set to face Montana De La Rosa on December 5 at UFC on ESPN 19, but De La Rosa was pulled from the matchup after a member of her corner team tested positive for COVID-19.
Santos expressed relief that she still gets to compete despite the long and challenging preparation period.
"I was quite upset about losing the De La Rosa fight since I'd spent three months preparing for it," Santos explained in an interview with MMA Empire through a translator.
"Without a replacement fight, it would have been a terrible situation for me."
Robertson sees Santos as a more favorable fight
At No. 13 in the women's flyweight standings, Robertson was originally set to fight No. 11 Lee—a chance to move up the rankings and solidify her position in the weight class.
Robertson acknowledged that a victory over Santos might not carry as much prestige as beating Lee, but she believes the new matchup plays to her strengths.
"Andrea was the harder fight. She's taken on tougher competition, she's a seasoned veteran, and she's been in this sport for a long time," Robertson noted.
"It works out slightly better for me that I'm getting someone whose ground game isn't as polished, and who seems more inclined to stay on her back based on her previous fights."
Though Robertson couldn't maintain her finishing momentum in her most recent bout—a unanimous decision victory over Poliana Botelho in October—she did break the record for most submission wins in women's UFC history with her rear-naked choke finish of Cortney Casey back in July. That record-breaking submission marked her fourth in the organization.
Robertson says she has bigger ambitions, aiming to surpass the all-time UFC submission record currently held by Charles Oliveira, who sits at 14 finishes.
"I'm building something special for myself," Robertson said.
"Obviously, the championship belt is the ultimate objective, but I don't just want to be known as a dominant champion. I want to be remembered as someone who holds numerous records that no one else can touch. Right now, other fighters are still too close behind me."
Her previous bout against Botelho marked the first time in her entire UFC tenure that she'd gone to a decision.
She intends to return to her finishing ways this Saturday with her preferred submission.
"Everyone knows I'm focused on ending fights, attacking the neck, and the rear-naked choke is my absolute favorite," Robertson said.
"That's our plan, and hopefully I can put her away before the final bell sounds."
Santos has rebuilt her confidence
Following a split decision loss to Mara Romero Borella in February 2019 during her UFC debut, Santos finally earned her first victory in the promotion by taking a unanimous decision over Molly McCann in July.
Entering this fight, Santos reports feeling more assured than she did heading into the McCann matchup.

"I feel very confident and comfortable heading into this fight. Last time, I wasn't comfortable because I was scared of losing again," Santos shared.
"That fear is gone now. I'm ready to show everything I've got, and I believe in my chances of winning."
Santos will move from facing No. 15-ranked De La Rosa to No. 13 Robertson, raising the stakes even further for a victory.
While she welcomes the high-profile opportunity, Santos doesn't intend to force her path to the top of the division.
"This is a great chance to showcase my talent, but I'm not fixated on rankings," Santos said.
"I know I'll get there. It might be now, or it might take a year, but I'll earn my title shot. I want to gain experience in the UFC and remain patient."
Entering this contest, Santos has demonstrated dangerous striking ability throughout her career, securing 10 of her 16 wins via knockout or TKO.
Santos acknowledges she holds a striking advantage over Robertson but remains assured in her grappling skills as well.
"I expect Robertson to try taking me down since her striking isn't very strong. She has decent wrestling and ground skills, but she's not a strong striker," Santos observed.
"My strongest area is standing, but I'm equally confident on the mat. I genuinely believe I can submit her."
Robertson's Shoutouts
"I always want to thank Din Thomas and Jose 'Shorty' Torres, my head coach and primary training partner. They've been with me through every challenge, and they're why I've reached this point." Follow Robertson on social media: FACEBOOK, TWITTER, INSTAGRAM
Santos' Shoutouts
"I appreciate everyone who supports me—my coaches, my gym, my friends, and my family. I guarantee a fantastic performance on Saturday night." Follow Santos on social media: FACEBOOK, INSTAGRAM


