T.J. O'Brien is a uniquely gifted prospect currently competing at 145 and 155 pounds. O'Brien hasn't followed the same career path as most of his peers, as his athletic background consists of track, basketball and show jumping. Those backgrounds however have proved beneficial in his MMA training, as he possesses excellent cardio, conditioning and strong legs. O'Brien began training in jiu jitsu after high school and has rapidly developed his mat skills and submission game. He's enjoyed a successful start to his MMA career and captured several titles including the Midwest Cage and Revolution Combat Championships.

O'Brien isn't overwhelming in his wrestling, takedowns or sprawl but he's a strong grappler who's very difficult to deal with on the mat. Aptly nicknamed "The Spider", O'Brien's equipped with long, flexible limbs and a very slick ground game. He shows good hips, nice balance, and makes good uses of his long frame on the ground. O'Brien is especially dangerous off his back as he wraps his opponents up in his legs and works a dangerous high guard. He's great at transitioning to his back, displays good wrist control and sucks his opponents in while throwing his legs up and working his subs and sweeps. O'Brien possesses a very tight submission game and sets up his attempts nicely. Given his active legs and excellent submission awareness, O'Brien is a very dangerous guard player. He transitions seamlessly between submission attempts, doesn't force anything (see his beautiful transition from guard, to triangle choke, to Americana against Jake Brown), and uses his elbows nicely off his back. O'Brien is armed with a fantastic triangle choke, with 13 of his first 14 wins coming via submission and 11 of those via the triangle choke. O'Brien would be well served by continuing to work on his wrestling, but he does have a very unique frame for his weight his division and his technical skills are solid.

O'Brien has shown he's comfortable standing, and encouragingly displayed an improving standup game over the course of his career. A 6'2" feather/light weight, O'Brien possesses a 78 inch reach on his feet that he's begun to use much more effectively as he's gained experience and confidence. O'Brien throws straight punches and a nice right cross from the outside. He also throws good leg kicks, while also possessing the ability to come up high with decent head kicks, and shows good knees from in close. Although he will require more polish, O'Brien is an intelligent fighter who appears to be on way towards developing into a competitive, and at the very least competent, MMA striker.