PHOENIX -AP- The Arizona Diamondbacks are parting with senior vice president of baseball operations De Jon Watson, and chief baseball officer Tony La Russa said he and general manager Dave Stewart may also be fired after the season.La Russa announced Watson's departure after a 10-9 win over the Dodgers on Sunday.La Russa said he will eventually meet with owner Ken Kendrick and president/CEO Derrick Hall about his status. "If it gets turned over the next person, you gladly turn it over," La Russa said. "When we're 20 games under .500, I felt if you're looking at the front office, the most responsible person, it would be me."Arizona made an aggressive push to compete in the offseason by givingZack Greinke a $206.5 million, six-year free-agent contract and trading a bevy of young players to the Atlanta Braves for right-hander Shelby Miller. Greinke is having his worst season in years, and Miller pitched poorly enough to get a midseason demotion to Triple-A, part of why the Diamondbacks are just a game out of last place in the National League West at 63-86."When you have this kind of year, I've never had a problem taking responsibility, and evidently, stuff that I've been taught hasn't contributed enough," La Russa said. "We'll wait and see how the decision comes. I'm ready to go forward if they've seen enough."Watson was in his second season with the club and oversaw the franchise's player development and professional, amateur and international scouting departments.La Russa said the team decided not to renew Watson's contract and let him walk before the end of the season so he can pursue other opportunities.