The Diamondbacks are considering the possibility of having O'Brien make the team's Opening Day roster, the Arizona Republic reports. While there is some debate regarding O'Brien's ability to handle the defensive rigors of catching, the Diamondbacks don't have the luxury of using him at first base with Paul Goldschmidt entrenched at the position. O'Brien spent time behind the plate during the Arizona Fall League, and the lack of viable alternatives currently on the big league roster -- Tuffy Gosewisch and Rule 5 selection Oscar Hernandez -- could pave the way for O'Brien to arrive in Arizona sooner than expected. Those plans are subject to change if Arizona acquires a more proven option before the start of the season, but the current indications from new general manager Dave Stewart point to a lack of interest in seeking help for the position outside of the organization at the present time. At the plate, O'Brien brings plenty of power to the table, as evidenced by his 34 home runs between High-A and Double-A in just 427 plate appearances last season, but his career .319 OBP as a minor leaguer suggests that his plate discipline is still a work in progress.