Once he joined the A's organization, he moved quickly through the ranks, reaching AAA-Sacramento by the end of the 2004 season. However, he returned to AA-Midland in 2005, where he batted .267 with five homers in 131 games for the Rockhounds.
Kiger was given a shot to stick at AAA-Sacramento as a utility player in 2006, but he struggled at the plate in 61 games for the River Cats. He hit .233 with only 11 extra-base hits in 176 at-bats. He did walk 30 times against 47 strikeouts, however.
Kiger was sent down to AA-Midland in mid-July, and the demotion seemed to liven up his bat. He helped get the Rockhounds into the playoffs by hitting .307 with a .450 slugging percentage in 58 games. It was arguably the best stretch of hitting for Kiger in his minor league career.
He was a month into his off-season when the A's gave him a call that they might need him to act as a back-up middle infielder in the ALCS. Oakland had lost Mark Ellis and Antonio Perez to injuries and needed someone to back-up Marco Scutaro and D'Angelo Jimenez. Kiger flew to the A's training facility in Phoenix and earned a berth on the ALCS roster with an impressive showing in the field. He made appearances in two ALCS games as a defensive replacement, becoming the first player since 1885 to make his major league debut in the post-season.
Kiger is a versatile fielder, who can play second, short and third effectively. He has been praised for his work ethic and for his ability to work the count.
Kiger is the type of player that the A's would likely have preferred to keep in their system, but he got caught-up in a numbers game. He most likely would not have been added to the 40-man roster this off-season if it hadn't been for the injuries the A's sustained during the playoffs. When the A's acquired Donnie Murphy and elected to tender contracts to Marco Scutaro and Antonio Perez, it appeared to be only a matter of time before Kiger was taken off the 40-man roster given the number of middle infielders the A's were carrying. Oakland needed the 40-man roster space when they signed free agents Alan Embree and Mike Piazza and added Rule 5 picks Ryan Goleski and Jay Marshall. The A's also removed Jerome Williams from the 40-man roster when he was non-tendered on Tuesday.
Kiger can now be signed by any team to any type of contract.