Arce is undefeated in all eight of his pro MMA fights (and undefeated in all 11 of his amateur bouts). He's also a Muay Thai champ, and though he specializes in finding openings on the feet with his sharp boxing skills, he's dangerous as hell on the ground.
On the flipside is Kelleher, who's fought in Bellator and a ton of regional promotions. A wrestler by nature, Kelleher knows his way around the submission game and is capable of banging it out when the need arises. He's got losses on his record, but he's been knocking his head against the regional ceiling for a while now, and beating Arce in impressive fashion would be just what the doctor ordered.
What makes this particular match-up so special is what the "W" will mean for each man. Defeating Kelleher shows that Arce can handle an accomplished veteran, which is the last piece of the puzzle for Arce's journey to Octagon Shangri-La. But the hype around Arce makes a win over him a special prize - the kind of prize Kelleher can use to parlay into his own UFC entrance.
We've seen this equation play out in ROC many times before (the most recent example would be the ROC 48 title fight between Chris Wade and Frankie Perez, both of whom ended up in the UFC not long afterwards). It's a lock that on September 25 we're going to see it again.
When the dust settles at ROC 52, either Arce or Kelleher will have punched their ticket to the UFC.