According to MMAJunkie.com the matchup is close to being finalized.
O’Brien emerged as a heavyweight up-and-comer with three-straight victories to start his UFC career, including a victory over veteran Heath Herring, but next suffered back-to-back losses to Andrei Arlovski and Cain Velasquez, the first two defeats of his young career.
After suffering a first-round knockout to Cheick Kongo in his UFC debut Wellisch rebounded to score back-to-back UFC wins over Anthony Perosh and Scott Junk. However, he was stopped by surging heavyweight Shane Carwin in just 44-seconds at UFC 84 in May.
The UFC welterweight title will be on the line in the UFC 94 main event, as UFC 170-pound champion Georges St-Pierre rematches 155-pound title-holder BJ Penn.