Possible Clues:

• Oakland team, to fans
• Oakland ballclub
• Oakland team, familiarly
• 1989 Series champs
• AL West team
• A.L. West team, familiarly
• 'Moneyball' team, for short
• Three-time '70s World Series champs
• MLB team, familiarly (and what's missing from the sequence found in the answers to starred clues?)
• Oakland squad